In its most general usage, the word tepid means “slightly warm.” Because of this, it is likely that you will be tempted by the options “lukewarm,” “chilled,” and “fire;” however, none of these provide an adequate antonym—not even fire, for that is not an antonym to tepid (as would be “blazing” or something else describing a great deal of heat). In addition to pertaining to physical temperature, “tepid” can likewise mean “unenthusiastic” (as though someone had a merely warm or even cool temperament). Thus, “enthusiastic” is the best option among those provided.

When someone has a voracious appetite, he or she is extremely hungry, being led to devour large quantities of food. In an extended sense, someone can be voracious for any given activity, in the sense that he or she is very devoted and eager in pursuit thereof. In contrast to such voracity, an “abstemious” person is one who does not indulge heavily, particularly in food or drink. This is the only appropriate antonym among the options provided.

The word “wretched” can mean “of poor quality” or “in a poor condition,” though it is primarily used to describe someone in an extremely miserable state of affairs (and likewise the mental state of sadness or dejection felt because of such conditions). Thus, the only antonym among the options provided is “joyous.” While “improved” and “edified” might be tempting, these do not directly contrast to the state of being wretched. Improvement and edification can help to remove someone from wretchedness. They are not, however, the opposite thereof.

As you well know, a “wobbling” object is one that is moving or swaying from side to side (or “jiggling,” perhaps). The point to note is that such an object is unsteady and unstable. In contrast to this, only “steady” is an acceptable antonym. Other options, like “tottering,” “oscillating,” and “jittering” describe other types of unstable motion. To “dampen” a motion will stop it, but this does not describe an antonym to “wobbling.”

The word “munificent” literally means “gift-giving.” More properly speaking, the English definition is, “the character quality of being very lavish and generous.” One could say, “Uncle Peter was extremely munificent to all of his relatives. Since he had no children of his own, he spent his extra money more lavishly among his other relatives.” In contrast with this, only “stingy” indicates a lack of generosity.  

When something is moderate, it is “in the middle.” A “moderately hot” beverage is one that is “relatively hot”—not too hot, not too cold. A “moderate opinion” is one that is not extreme—not (for example) too conservative, not too liberal. The key notion associated with moderation is that of being “in the middle” and not being extreme. While many of the options are perhaps related to immoderation—for instance, argumentation and being too political—only “exceptional” is directly opposed to “moderate.” When something is “exceptional” it is unusual and “stands out”—which is quite the opposite of being moderate.

To initiate an action is to begin to undertake it, as when someone “initiates the warning sequence in response to a fire.” The word can be used also to describe the process of beginning to teach someone how to do some task or to live in some group. Rights of “initiation” bring people into the beginning of some kind of activity or lifestyle. The “uninitiated” are those who have not been so instructed or (perhaps) inducted into the lifestyle or activity. The only real antonym among the options provided is “instructed.”

When something is “rational,” is reasonable and makes sense according to logical thought. Thus, in contrast to rationality, one can speak of being illogical, meaning that such a person does not think in a coherent manner that is communicable. An illogical person is irrational, that is, not reasonable.

Likely you know the word “hesitant” or at least the related “hesitate.” To be “hesitant” is merely to be in a state of doubt or uncertainty regarding a potential undertaking or course of action. For instance, you could say, “Thomas was hesitant to read the book; he doubted the credibility of the author and did not want to waste his time parsing through half-truths and outright lies.” In contrast to being hesitant, someone who is “determined” is certain that a given decision should be made. Such a person has no hesitations—at least the he or she expresses explicitly.

Something that is “incriminating” implies that a person is guilty. For instance, “incriminating evidence” in a trial is used to show that a person could indeed be guilty of a crime. The word literally could be read in the sense “in + criminating,” the latter portion being related to the word “criminal.” It is as though such evidence leads one into the status of being a criminal (at least in others’ eyes). Something “exculpatory,” on the contrary, shows the innocence of a person. The word “culpable” means guilty, so “exculpatory” could be read as “getting out of (ex-) the state of guilt (-culpatory).”