Answer:
A. Inability to act.
Step-by-step explanation:
A tragic flaw is a character trait that leads to the downfall of the character. This is also known as "hamartia", and this characteristic is what leads to the fall of the character from high to low.
William Shakespeare's "Hamlet" revolves around the story of a young prince Hamlet who wants to avenge the death of his father. But despite his urgency to do the deed, he is unable to act at the exact time. He wants to act but at times, got caught in a dilemma whether to do it or not. This inability to act makes him a tragic flaw, which eventually led to his downfall.
Thus, the correct answer is option A.