Suppose a Crow Normally Uses 50 Energy Units to Extract

Multiple Choice

Suppose a crow normally uses 50 energy units to extract larvae from holes in trees and only 5 energy units foraging for nuts. The crow can get 60 energy units from eating larvae and 15 energy units from eating nuts. The crow can decrease the amount of energy used to extract larvae from holes to 5 energy units, but only if it first spends 15 energy units building a tool. In which case does the crow obtain the most net energy?

A) When the crow forages for larvae without a tool
B) When the crow forages for nuts
C) When the crow forages for larvae with a tool
D) When the crow forages for nuts with a tool