The correct answer is B. Rising action
Step-by-step explanation:
In the development of a story and the events that are part of it or plot, the rising action refers to the event or events that lead characters to the most difficult or challenging point in a story called climax. Because of this in the plot, it is common to find character took certain decisions that lead to a twist in the story, although this can also occur as the result of background circumstances. This features can be seen in the excerpt presented because the character knows everything will change which is probably the climax of the story and despite this, he approaches the door, which means the actions of the character lead him to the highest point of conflict or action and therefore this is part of the rising action.