A college psychology professor who gives a test every two weeks illustrates the process of a. fixed-interval schedule (FI).
b. variable-interval schedule (VI).
C. variable-ratio schedule (VR).
d. fixed-ratio schedule (FR).

•there must be variation for the particular trait within a population.

•the variation must be inheritable (that is, it must be capable of being passed on from the parents to their offspring).

•individuals with one version of the trait must produce more offspring than those with a different version of the trait.good

explanation:

z is the answer.

(sorry caplock) lol

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