Which theory/hypothesis suggests that strong emotions trigger the formation of strong memories, and weak emotional experiences form weak memories? engram hypothesis arousal theory flashbulb theory equipotentiality hypothesis?

The answer is arousal theory

Arousal theory is a motivation theory that state human motivation changes from day to day hence high arousal events are remembered better than low arousal events. This applies the same way to human emotions where by strong emotions form strong memories while weak emotions form weak memory