I'm going between answer A and C, because usually a reduction of ones habitat anymore is due to human impact instead of temperature.
A would be a good answer because if more and more land was being lost to the gators, they would have to dwell in the water more.
C also would be a good answer because if something major was to happen to the gators, such as a sudden decrease in land and/or water habitat, they might not be able to handle the sudden change and die.
The inference I can make is that since the people in the annex started to run out of food so they started to divide it even more which can cause trouble since some want more than others.
Because Robinson is a black man accused of raping a white woman, the white residents of Maycomb are furious that Atticus, the town's best lawyer, would choose to help his cause.