Final answer:
The correct answer is option B: Our class is preparing their reports to share at the outing on Friday.
Step-by-step explanation:
Option B: Our class is preparing their reports to share at the outing on Friday.
Collective nouns such as class can take a singular or plural verb depending on the context. When the group acts as a single unit, use a singular verb.
However, when the group members act individually, use a plural verb or add the word 'members' for clarity. In this case, since the sentence is referring to the class as individuals (preparing their own reports), the correct sentence is option B.