Which of the following represents a population,as opposed to a sample?

A) 2,000 respondents to a magazine survey which has 600,000 subscribers.
B) The first 15 students in your class completing a final exam.
C) Every fourth student to arrive at the book store on your campus.
D) All registered voters in the state of West Virginia

A population refers to the entire group of individuals or objects that we want to study, while a sample is a smaller group or subset of the population that is actually studied. Choice D represents a population because it includes all registered voters in the state of West Virginia, which is the entire group of interest. Choices A, B, and C are all samples, as they represent smaller subsets of a larger population.