You spelled it correctly. It is "hippopotamus".
I'm sorry I can't help, but I hope you got it right.
Plus a tip... most people won't answer it because it is really long
The best punctuation that makes the most sense is B. Use the hyphens so that you can separate the main purpose of the sentence from the adjective.
Although these verbs sound a bit different, they are both in the present tense, so the answer is "A. The verb tenses are consistent". If it was "had approached" the tenses would be different.