What does the phrase "maddened by despair " mean as it used in a text

Apopulation of deer mice was introduced into a desert ecosystem. being dark-colored, the deer mice stood out in the sand and were easy prey for predators. over a few years, the color of the mice changed from dark brown to light brown. what role does natural selection play in this example? a. the change of color camouflaged them, which them hunt better. b. the change of color enabled them to regulate their body temperature. c. the change of color allowed them to hide better from predators. d. the change of color made their bodies tolerant to the harsh desert sand. e. the change of color allowed them to deflect the excessive heat.