When something is "sleek," it is smooth. We do use the adjective to describe things like "sleek hair", often implying that it has a kind of oiled, smooth look. The primary meaning of "sleek" is smooth. Now, this meaning can then be extended to mean elegant or graceful—like smooth lines that are well drawn. This is the only option that works for this question.

Whenever something is "rigid," it is unbending. A rigid piece of wood is one that is very stiff. We use the word also to describe someone's habits. A person of "rigid" habits is a person who does not change his or her ways of acting. This is the sense in which the word is being used here. None of the other options match the notion of being rigid except for "unchangeable." 

The word "radiant" comes from Latin roots meaning to shine or (more obviously) to put out rays. Hence, we speak of the sun as being "radiant" because it shines out "light rays." Likewise, we talk about "radiant heating" because the source of heat puts out infrared rays (or "heat rays"). This word can also be used to describe someone who is very happy, as when we say, "Thomas was radiant when he was told that he won the award." This is the meaning for this question, and "jubilant" is a good synonym, as it means full of joy. Think of it like someone shining with "joy rays"!

You are likely most familiar with the word "circulate" from its use in biology or anatomy. Blood circulates in the body, meaning that it "goes around" through the whole body. As the word clearly indicates, it makes the "complete circuit" or the "full circle" of the body.

However, things like news can be said to circulate as well. By this, we mean that the news "gets out." Whenever a rumor circulates, it is told to many people. Hence, the word "circulate" can have "communicate" as a synonym. Do not be tricked by the options that seem to be related to anatomy as well as blood—such as "embodied," "bleed," and "seep." None of these words are directly about the actual movement of things, as is indicated by the word "circulate."

The word "cement" is most familiar when it is used to describe the kind of hard material that we often see in sidewalks and as a general building material; however, the word generally indicates the process or material that helps something to "stay in place." Hence, as a verb, you can even use the word "cement" to describe something like a business agreement or a relationship. Multiple people can get together to put together an agreement. When it is "cemented," it has been firmly established. You can think of it like being "rock-hard" like the building material with which you are likely familiar.

We tend to think of being "buried" in terms of physical burial. Whenever someone dies, his or her body is buried in the ground. This means that it is placed under the soil. It is this general sense of "placing under" that is the root of the meaning being used here. Whenever someone "buries" his or her feelings, that person hides them—sometimes even from himself or herself. Hence, the word "buried" could have "concealed" for one of its synonyms, as it does in this question.

When something is "sleek," it is very clean and smooth. It is often used to describe the kind of smooth hair that a person or animal can have when we say that it is "slicked back"; however, this kind of clean and smooth appearance can also indicate that something is "in style" or at least elegant (as opposed to something that is a total mess). This is the way "sleek" is being used in this question, for the only acceptable option is "stylish."

The word "convey" is interestingly related to the word "convoy," which describes a group of vehicles that travel together. The word "convey" most generally is used to express the idea of carrying or transporting something; however, it can also be used in an extended sense meaning to communicate—as though words can "transport" meanings from one person to the next. It is in this latter sense that the word is used here, for the only acceptable option among those provided is "reveal." When we ask, "Did you convey the meaning to Bob," we could translate this as, "Did you communicate the meaning to Bob," or as, "Was the meaning revealed to Bob?"

There are two senses of the word "plot," and you must not confuse them when answering this question. On the one hand, "plot" can indicate the storyline of a book, play, movie, or other type of media. Several of the options are concerned with stories—"antagonist," "narrator," and "protagonist"; however, none of these words are synonyms for "plot" in this sense.

On the other hand, "plot" can be used to describe a piece of land, as when we say, "He bought a plot of land in the wilderness." This means that the person bought a bit of land out in the woods. Although "parcel" can describe a package, it can also be used as a synonym for a piece of land. It is in this sense that it is being used in this question.

The word "plot" has several meanings. One main cluster of meanings has to do with areas of land—as when someone lives on a "plot of land." This, however, is clearly not the meaning intended among the options provided here. Instead, the options hint at another primary meaning to the word, namely, the storyline of a play or other drama. A scenario is a sequence of events—how they happen one after another. Often, the word can be used to describe a plot of a story as well (since stories are, in fact, sequences of events). Therefore, it provides an excellent synonym for "plot" as it is used in this question.