A flashback tells something from the past so the answer would have to be (A) this is because of the use of the word recall. In every other option the verb is present or future tense instead of past tense.
Increased traffic on city streets leads to longer commuting times for students.
Participitating, its a gerund, and it isn't a direct object
You can do a fundraiser or do a lemonade or yard sale.That's what they did for the hurricane victims in the Katrina tragedy.
