Answer:
If a student would like to be part of the class play, C. he or she should come to the drama room this afternoon.
Step-by-step explanation:
Option C. he or she should come to the drama room this afternoon is the correct option, because it is the only sentence that provides the appropriate subject to make reference to the antecedent "a student." "A student" refers to a singular, 3rd person subject, and the only sentence that provides that option is "he or she..."