The optimality theory suggests that
a. animal behavior is based on nature
b. animal behavior is based on nurturing
c. beneficial behaviors are passed on for generations
d. only a mutation can prevent weak behaviors from being passed on for generations

c. beneficial behaviors are passed on for generations

The optimality theory is the theoretical concept that states that behaviors that a fit is the behaviors that are passed thru generations. Although, behavior is subjected to change due to various factors such as the environment, culture, norms and other sociological elements. The natural selection theory in contrast is different, different in the sense that natural selection happens when an organism is forced to adapt due to certain selection forces.

It should be cryosphere and hydrosphere

Mg is used to measure mass