Answer:
A compromise
Step-by-step explanation:
The options you were given are the following:
- a compromise
- an intervention
- an act of revenge
- an argument
An external conflict is a conflict that takes place between the protagonist and some outside force, most often the antagonist or society. The plot event that would most likely cause the protagonist to develop as a character is a compromise. Instead of completely going against his opponent, he could try understanding his side and work with him in order to find a solution the both of them could benefit from. This scenario would build empathy, compassion, and other virtues within the protagonist.