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.
