Which plot element includes the events that occur after the main character made the key decision in the story

Falling action.

Explanation:

The falling action occurs in a plot right after the most intense and decisive element of the story i.e. climax. The climax includes the key decisions that have lead to the turning points in the story while falling action takes the story towards the resolution of the conflicts followed by denouement and conclusion. It leads the plot towards a sense of closure(wrap-up) and offers to resolve the loose ends of the plot. This exemplifies the narrative plot followed by the climax and before conclusion and denouement. Thus, the decisive events of the story are followed by the falling action.