It is important to make sure that your synonym is not too strong of a word. When we "irritate" someone, we do not make that person very angry. We are not looking to make him or her "enraged" or "infuriated." We are merely bothering that person, making him or her "a little angry." We are annoying that person. Now, "anger" is actually a decent synonym, but "annoy" is better and therefore is the answer for this question.

For this word, you must pay attention to the intensity involved in the meaning of "clutch." When we "clutch" on to something, we hold it tightly and firmly. Thus, options like "retain" and "hold" are far too weak to describe the action of clutching. The best option is "grip," which also means to hold onto tightly.

When you "crave" something, you really desire to have it. For example, you can say, "I really am craving chocolate." This means that you really want to eat a lot of chocolate. Thus, "to crave" means to desire greatly. Among the answer choices, only the simple "desire" is a good option.

To "eliminate" something means that you get rid of it. For example, you could say, "I wanted to eliminate the possibility of failure." This means that you wanted to prevent any possibility of failing. Therefore, in general, the idea of eliminating has to do with removing.

The word "obtain" means "to get." Most often, we use the word "acquire" to indicate that we are buying something. For example, we can say, "I acquired two new pairs of shoes for summer;" however, in addition to meaning that you bought the shoes, it can also mean merely that you have now received them or have gotten them. Therefore, "acquire" is a good synonym for "obtain."

When we "permit" something to happen, we allow it to happen. For example, you might say, "The mother permitted her child to have three pieces of candy after dinner." This means that she allowed the child to have those pieces of candy. Thus, "allow" is a correct choice for the synonym.

The word "mangle" describes the action of severely hurting someone or something. For instance, you could say, "The pillow was mangled by the lawn mower that ran over it." The only option that communicates this kind of destruction is "damage."

When something "shimmers," it shines on and off. For example, light might shimmer on the surface of water. It has a sparkling look. This same kind of look can be called "glistening" as well. Hence, the verb "glisten" is the best synonym. 

When someone or something is revered, it is respected. For example, you can say, "David revered his mother, for she had sacrificed many things so that he could have a good life." This means that he had a high opinion of his mother. It would be appropriate to say that he admired her. This is the best option among those given.

An "assistant" is someone who helps another person to do his or her task. When we "assist" others, we provide such help, which might also be called support. For example, "I assisted her with her baking," could be translated, "I supported her work at baking."