Which of the following is not required for a simple random sample from a population of 20 individuals? a. Each individual in the population has a 1/20 probability of being selected. b. The selection...

Which of the following is not required for a simple random sample from a population of 20 individuals?

a. Each individual in the population has a 1/20 probability of being selected.

b. The selection of one individual is independent of the selection of any other individual.

c. After 20 selections, each individual must have been selected exactly one time.

d. The individual obtained on any specific selection must be unpredictable.