Hine' s emerald dragonflies are an endangered species that live in wetlands. The larvae of these dragonflies can survive only in the water, where they are subject to predation by several species including red devil crayfish. Surprisingly, the dragonfly populations are more likely to remain healthy in areas where red devil crayfish are present than in areas without red devil crayfish. Which one of the following, if true, most helps to explain the surprising fact?
A: Populations of red devil crayfish in a wetland do not drop significantly if the local population of Hine's emerald dragonflies dies out.
B: Red devil crayfish dig chambers that remain filled with water even when the surrounding wetlands dry up.
C: Red devil crayfish present no threat to adult Hine's emerald dragonflies.
D: The varied diet of the red devil crayfish does not include any animal species that prey on dragonfly larvae.
Choose A, B, C or D as your solution.
B