Final answer:
The correct pronoun to complete the sentence is 'himself' since it must agree in number and gender with the singular male antecedents 'Richard' or 'Luke'.option c is correct answer.
Step-by-step explanation:
The sentence in the question is "Either Richard or Luke has already bought ______ a new jacket this fall." The correct pronoun to complete this sentence is "himself" because the subject "Either Richard or Luke" requires a singular reflexive pronoun that matches the male antecedents "Richard" and "Luke."
The correct option is thus: "Either Richard or Luke has already bought himself a new jacket this fall." The pronouns "themselves" and "theirselves" are plural and not appropriate in this context, whereas "correct" is not a pronoun.
In addition, the Review Questions provided help illustrate the proper use of possessive pronouns and reflexive pronouns, as well as correct punctuation involving apostrophes and the avoidance of gender-biased language.