Choose the correct answer below.
a. a sample is a set of measurements that are recorded on a naturally occurring numerical scale. a population is a set of measurements that cannot be measured on a natural numerical scale; they can only be classified into one of a group of categories.
b. a sample is a set of units of interest to a study. a population is a subset of the units of a sample.
c. a population is a set of units of interest of a study. a sample is a subset of the units of a population.
d. a population is an object upon which data is collected. a sample is a characteristics or property of an individual experimental unit.