The answer is A., it makes it feel as if you're shouting at the reading. Exclamation marks are used to show lots of emotion, as sometimes it is also used for shouting.
B., C., and D. all are completely not related.
Your opinion can be expressed with exclamation marks, it won't confuse anyone. Like I said, exclamation marks are used to show lots of fire and emotion. It wouldn't confuse anyone.
Exclamation marks do not confuse the main point. The reasoning for why it isn't C is similar to the reasoning for B. Exclamation marks do not change the main point.
C. is pretty much the opposite. Exclamation marks are used for emotions, not to show no emotion.
The speaker of a poem is sometimes the poet
This isn't neccessarily true. Your introduction can still make sense without the hook, and the information inside the introduction part should really not directly depend on the hook to explain them, they should either be self explanatory, or you should explain them there.
Hopefully this helps!
You didn't italize or mark the phrase, but I see one good candidate:
"The circus animal trainer" is in a way another name given to Mervin, a kind of "renaming" him: this is called an appositive phrase, so if this was the phrase appositive phrase is the answer! (also, I don't see the other phrases here).
