When someone “registers an objection,” that person expresses opposition to some point of view, fact, etc. To say, “I object . . .” is akin to saying, “I disagree . . .” In contrast to objection, “concurrence” is the state of being in agreement. It literally means “to run with,” as though to say, “to be going in the same direction.” The current of a stream is the “running” of the water in the stream. To say, “I concur,” is basically the same as saying, “I agree with you.”  “Concurrence” is thus an excellent antonym for “objection.”

"Recent," "renege," and "forswear" are synomyms of abjure. "Abjure" means to renounce or give up under oath. "Emphasize" means to lay stress upon something.

"Aggravate," "infuriate," and "anger" are all synonyms of antagonize. "Antagonize" means to provoke hostility. "Pacify" means to soothe.

Someone who is “dutiful” is someone who attends to the requirements of his or her station of life. That is, he or she follows through on his or her duties. Perhaps you have heard the expression, “dutiful son,” used by someone who claims to do everything that should be done by a child for his or her parents. The opposite of someone who is “dutiful” is someone who is “negligent.” The word “negligent” is related to the word “neglect” and could even be thought of as “neglectful,” though it is better defined as not taking proper care of given matters. This is an excellent antonym for “dutiful.”

"Emancipation" is the act of freeing someone who is restricted or enslaved. For instance, one can speak of being emancipated from the overbearing rules of a government or family. Often, the word is used in its more literal meaning, namely that of freeing from slavery, as in the Emancipation Proclamation of Abraham Lincoln. The opposite of such an act of freeing is “incarcerating.” The word “incarcerate” literally means “into jail,” the “-carcerate” portion coming from the Latin for jail. Incarceration is the state of being placed into such a state / circumstance.

Someone who is "dispassionate" is relatively unemotional, not being swayed very easily by passions. (Hence the name, which means lacking passions). This is quite opposite to an avid person. The word “avid” is derived from a Latin root meaning to crave. It is likewise related to "avarice," meaning greatly greedy. In English, “avid” means enthusiastic or passionate. The words “angry” and “enraged” are too specific. “Avid” is a better, more direct, antonym.

When someone is "candid," he or she is completely honest in an open manner, not having any barriers that might hold back the truth. For instance, if someone recently got a very bad haircut but wanted to know if it was bad, he could ask a trusted friend, “Give me your candid opinion. Do I look like a fool because of my new haircut?” This is like saying, “Don’t hold back just because you are my friend. Tell me the truth.” When someone is "guarded," he or she cautiously protects or hides some aspect of his or her character or thoughts. Likewise, a guarded person is someone who is very careful in any action. This is sufficiently opposite to “candid” for our needs.

When something is done "flagrantly," it is done in a manner that is very open and conspicuous, often with the sense that the person doing it is aware that the action is morally or legally unacceptable. You have likely heard the expression, “Flagrant violation of the law.” An example of this would be, “John committed a flagrant violation of the traffic law with glee. After commenting on the 45 mile-per-hour speed limit, he pressed down the accelerator and began driving at 90 miles per hour, commenting that he would never obey such a stupid law.” Among the options provided, only “concealed” gives us some sense of contrast with “flagrant” insofar as something concealed is not admitted “in the open,” as is the case with something flagrant.

The word “hardy” is sometimes used in the expression “hale and hardy,” meaning healthy and strong. The word originally derived from roots meaning to be or become bold. The word “robust” is often an synonym for hardy, meaning, vigorous, forceful, healthy, or forceful. In contrast to such strength, something "fragile" is easily broken, harmed, or debilitated. This word is the best antonym among the options provided.

When something is "pertinent," it is relevant or applicable to a given situation. For instance, you could say, “The facts that Harold cited were not pertinent to the topic of his report and thus were distracting additions that added nothing to the overall discussion.” Although “immaterial” can mean not material in the sense of being spiritual or perhaps ghostly, the word also can mean irrelevant or not important (at least in a given set of circumstances). You could say, “Your objection is immaterial, for you are not even focusing on the problem that I am considering.” This is the only antonym among the options provided.