It is a learned behavior that maintains the population. It is a learned behavior that maintains salt concentrations. It is an inherited behavior that maintains the population. It is an inherited behavior that maintains salt concentrations.
Which statement explains why most salmon leave salt water and return to fresh water?

Options:
- It is a learned behavior that maintains the population.
- It is a learned behavior that maintains salt concentrations.
- It is an inherited behavior that maintains the population.
- It is an inherited behavior that maintains salt concentrations.

It is an inherited behavior that maintains the population.