Answer:
Remember when . . . you threw the pass that won the state championship?
Step-by-step explanation:
Informal style of writing is when there is the use of short sentences, colloquialism, contractions and even slang words and ellipses in one's sentences. It may also be when a writer is writing in such a way that he or she is directly addressing the readers. But this doesn't comply with the given sentences, considering that none of them used colloquialism, or even slang words or contractions. But the only sentence that can be deemed an informal style of writing is the second sentence. This sentence directly addressed the readers, or so it seems, and uses an informal means of speaking in personal tones.
Thus, the correct answer is the second sentence.