The prefix clar- means clear and the suffix -ify means to make into. So, to "clarify" something means to make it clear, to make it able to be understood. This is closest in meaning to "explain." Additionally, "salvage" means rescue, save, particularly save from being thrown away; "hesitate" means delay, pause; "inquire" means ask about, question; "occupy" means take up the space of. 

The prefix vis- means see, sight and the suffix -ible means able to be. So, "visible" means able to be seen. This is closest in meaning to "clear." Additionally, "dense" means thick; "acute" can mean sharp, clever or severe, intense or it can describe an angle in mathematics that is less than ninety-degrees; "obtuse" can mean stupid, not clever or it can describe an angle in mathematics that is more than ninety-degrees, but less than one-hundred-and-eighty-degrees; "parallel" means in line with, a line that runs alongside another line.

The root -cis- means cut. As in "concise" which means cut to the point, exactly to the point. So, an "incision" is a cut made in something.

The prefix pro- means push and the suffix -pel means forward, through. So, to "propel" means to push forward or simply to push. Additionally, "gather" means collect; "replace" means get a new version of something else, take the old place of; "donate" means give to (charity).

The prefix contra- means against and the suffix -dict means speak. So, to "contradict" means to speak against, to argue. Additionally, "vent" means express frustration, let off steam; "vend" means sell; "waver" means to be unsure of oneself and frequently be changing one's mind. 

The prefix in- means not and the root -anima- means life. So, "inanimate" means not living, lifeless, devoid of life. Additionally, "horrendous" means terrible; "painstaking" means done with careful attention to detail; "lethal" means deadly; "frail" means weak, sick.

The prefix inter- means between and the suffix -sect means cut. So, to "intersect" is to cut in the middle of something, to make a cut between two things. This is closest in meaning to "divide" which means to split, to cut in half. Additionally, "outlaw" means ban, forbid; "replenish" means refill, fill something up; "remain" means stay; "outline" means give a summary of something, show the main points. 

The word "inspect" is related to words like "spectator" and "spectacles."  A "spectator" is someone who watches something (like a football game), and "spectacles" are glasses that we use to help our vision. The root "spect-" often has this sense of meaning to look at. Thus, to "in+spect" means to look into something. It means that you look into the details carefully. This is best expressed by "investigate."

The word "verify" comes from the Latin for true. The word "very" means truly, and the "verdict" in a court case is the statement of truth (at least how it is judged to be true). Thus, to "verify" means to prove to be true. The best option given in this question is to confirm. When something is "confirmed," we know that it is the case. (Indeed, the word itself helps to express this sort of meaning—it proves that something is firm or certain.)

The options given for this question are all verbs. When someone "wonders" at something, he or she is amazed by it. For example, we could say, "He wondered at the beauty of the sunset." This means that he was amazed by it. Amazement can also be called admiration. Indeed, the word "admire" comes from the same roots as the word "miracle", meaning something wonderful. Thus we can "admire" something in the same way that we can "wonder" at it.