Explain how populations and variables differ. Choose the correct answer below.

Explain how populations and variables differ.

Choose the correct answer below.

A.      A population is a set of units of interest to a study. A variable is a characteristic or property of the units being studied.

B.      A variable is a set of units of interest to a study. A population is a characteristic or property of the units being studied.

C.      A population is a set of units of interest to a study. A variable is a subset of the units of a population.

D.      A population is a set of units of interest to a study. A variable is an object upon which data is collected.