The correct answer is B. Niether Mike nor Marvin believed in Superman. Based on these sentences, I can see that you are working on how to spell letters I and E next to each other. You've probably learned the rule 'I before E except after C,' as in <em>believe, fierce, die, </em>etc., however, you can see that this is not always the case, as in the options above. Neither is spelled with E before I, not the other way round.
I sharpened my skills under the mentorship of my coach. You need a noun to complete this sentence, and mentorship is the only noun here - the rest of the words are adjectives.
