The aye-aye lemur is a mammal that feeds mostly on insect larvae that live inside trees. The aye-aye lemur has a specialized middle finger that is long and thin. The aye-aye lemur moves along a tree branch and taps the branch with its specialized finger. When the aye-aye lemur hears a difference in the echo, it will tear open the bark with its teeth until the insect tunnel is exposed. The aye-aye lemur then uses its specialized finger to reach the insect larvae and remove it. Which selective pressure most likely resulted in the development of the aye-aye lemur's special adaptation?
A. Limited availability of water
B. Competing for mates
C. Large numbers of natural predators
D Food sources that are hard to find