Systematic Sampling Is Best Described by Which of the Following

Systematic sampling is best described by which of the following?

A) The random selection of subjects from two or more strata of the population
B) Involves the selection of subjects by including every nth person in a list
C) Provides a sample, through personal judgment, of subjects who would be most representative of the population
D) Provides a group of individuals who are most readily available to be subjects in the study