Some aquatic organisms that live in cold environments similar to that of crabs have multiple forms of certain enzymes that catalyze reactions at various temperatures. Explain how having multiple forms of enzymes would contribute to the fitness of these organisms.

The multiple forms of enzymes help in maintaining the homeostasis in cold environment.

Explanation:

The homeostasis is the process or the ability of the body to maintain the internal environment constant with respect to the changes occurring in the external environment. Some aquatic organisms which survive in cold water environments are required to maintain the homeostasis to survive. Multiple enzymes help them to maintain the homeostasis. Such enzymes allow the catalytic break down of fats and other biomolecule to generate internal body heat so that the aquatic organisms like crabs can maintain their body temperature constant with respect to the cold environment, this is a kind of adaptation.  

a and c are the answeres