Answer:
B. The inner conflicts of a character
Step-by-step explanation:
A Flash back is just a different way of storytelling and can be just as linear. An event based on hysterical facts doesn't necessarily means it will be exciting. A fight is action.
Inner conflicts are moments that the character wonders if he or she is in the right path and can bring up many philosophical or ethical debates over topics that the reader maybe never thought of and it can be quite interesting.