Him, His, He. These words are masculine because they are used to refer to the male figure.
Answer: I would contend that the right answer is actually "to fake."
Explanation: Just to elaborate a little on the answer, it can be added that one of the meanings of the verb to affect is to feign, which can be translated as to pretend or to give a false appearance of something. If the character was trying to "conceal certain inconvenient emotions" which, nevertheless, "seemed inclined to assert themselves" by affecting high spirits, he was, therefore, faking those high spirits, in order to hide his true feelings from the people who had just arrived.
Answer C should be capitalized, because it's a title of someone.
