Answer:
A. Jane is planning her college schedule, something you need to do when you register for classes.
Step-by-step explanation:
Pronoun antecedent agreement occurs when the pronoun matches in number with the noun it refers to. In that respect, sentence D contains the pronouns you (second person singular or plural) to refer to Jane (third person singular), which also affects the conjugation of the verbs. As a result, the correct version of the sentence is the following:
Jane is planning her college schedule, something she needs to do when she registers for classes.