Answer:
Mr. Thompson is now accepting applications for <u>his</u> yearbook staff.
Explanation:
Pronouns are words that replace nouns in sentences. Pronouns that express ownership are called possessive pronouns. They include pronouns <em>my, mine, our, ours, its, his, her, hers, their, theirs, your </em>and <em>yours</em>.
When we want to express something that belongs to a female, we say that something is <em>her/hers</em>. When something belongs to a male, it is <em>his</em>. In the given sentence, the subject is a man (Mr., or Mister Thompson), so the appropriate possessive pronoun is <em>his</em>: <em>Mr. Thompson is now accepting applications for </em><u><em>his</em></u><em> yearbook staff.</em> Had the subject been a female (e.g. Mrs. Thompson), the sentence would've been correct.
