Answer:
The theme is developed during the climax.
Step-by-step explanation:
The other answer is obviously wrong because the character's actions also form the theme. If the theme was to do good but the main character only did bad stuff it wouldn't make any sense at all.
The climax is the highest tension point of the story which is most likely to give us hints to the theme.
Not to mention I did the test myself and got it right.