"Placid" means calm or peaceful. "Tranquil" also means calm or peaceful. For example: "The placid lake made Sienna feel calm and tranquil."

"Saints" or "lakes" can both be called "placid," but they are not synonyms for this word.

The word "loquacious" can be used to describe someone who talks a lot. If you pay attention to the words that are not the correct answer, none adequately describes a loquacious person. Both "quiet" and "sullen" refer to someone who experiences a moment of silence and even sadness, and are thus antonyms to "loquacious;" "redundant" refers to something that is repetitive, and "exceptional" to something that is above average. The process of elmination should have helped you to answer this question.

"Sleazy" means immoral and corrupt, sordid and unpleasant. To provide further help, "porous" means easily penetrated, easily passed through; "diverse" means varied, different; "feisty" means unexpectedly tough, a strong individual who is relatively small; "reluctant" means unwilling. 

"Hapless" means unlucky, consistently unfortunate. You will have noticed that all the answer choices begin with the prefix un-. This is a negating prefix, this means it takes the original meaning of the word and causes it to mean the opposite. For example, "unkind" means not kind and "unpleasant" means not pleasant. Other prefixes in the English language that often have this impact are in- and im-. 

Someone who is "overbearing" is arrogantly dismissive of other's viewpoints, dominating and bullying. To provide further help, "illustrious" means acclaimed, well regarded, highly-praised; "undocumented" means not recorded, not written down; "vogue" means popular, fashionable; "caustic" means sarcastic and bitter.

"Prodigal" means wasteful, spending money needlessly and wastefully. To provide further help, "lawful" means within the law; "dreadful" means terrible; "scornful" means mocking, contemptuous, expressing dislike; "harmful" means causing harm, not helpful.

Whenever someone is "candid," he or she is honest. Whenever someone has a "candid" personality trait, we say that he or she has candor. These words actually come from the Latin for white. Whenever we are honest or candid, we do not "color over" the truth. We just speak the truth honestly (often bluntly and directly). Thus, the best option for this question is "truthful."

Perhaps you have heard the expression "an astute observation. "For example, someone might say, "The teacher was impressed by the astute observation made by Susan. Her remark was insightful and intelligent." Whenever we are astute, we are able to understand a situation or topic quickly and ably. Often, we are able to use that knowledge to our own advantage. For this question, however, we do not need to worry about this second part of the meaning. The only option that expresses a synonym for astute is "insightful." Even if someone is reflective, this is not the same as being insightful. A reflective person is someone who can think about things deeply. Often reflective people can be astute, but the word "reflective" is not as good of a synonym for "astute" as is "insightful."

Whenever someone is "charming," we like to be in his or her presence. A "charming" attitude or demeanor is one that is pleasant and likeable. When we are "charmed" by something, we are "pleased" by that thing (and often desire to have it). Thus, the best option among those provided is "pleasing." Whenever someone says, "He is a very charming person," he or she likely means, "He is very pleasing to be around."

The word "obnoxious" is related to the word "noxious." Whenever there are "noxious" vapors in an area, these vapors are unpleasant in odor and perhaps even dangerous. A person who has an "obnoxious" personality is annoying and displeasing to be around. Indeed, such a person can really be horrible company, and that is the sense implied in this question. We tend to think of foolish people as being obnoxious; however, this does not mean that these two words are synonymous with each other. Instead, the foolishness is the cause of the person's being obnoxious. Hence, the only option that really expresses the idea of being unpleasant is "horrible."