You use preterite to describe an action that took place and was fully done, Ex. José entro a la habitación, you can see John went into the room, he completed the action. On the other hand, imperfect tense doesn't specificate if the action was completed, Ex. José entraba a la habitación, it doesn't tell us if José fully entered the room.
At 2:45pm, it would be la clase de música
It’s hard to read all of the answers from the picture quality, but the correct answer is “a ti te”. Hopefully that is an option!
