Answer:
The sentence that has an incorrect shift in pronoun-antecedent agreement is:
B) Students must see his counselors before the end of the semester.
Step-by-step explanation:
A pronoun has the purpose of referring to a previously mentioned noun, substituting it. Thus, it must agree with that noun. As we can see, in the sentence "Students must see his counselors before the end of the semester," the noun to which the pronoun must refer to is "students" since it is the students who have counselor. "Students" is a third-person plural noun. The third-person possessive pronoun that would correctly refer to it is "their". "His" is singular and, for that reason, is incorrect. The correct sentence is:
Students must see their counselors before the end of the semester.