In the Context of Nonprobability Sampling,what Is an Element

In the context of nonprobability sampling,what is an element?

A) It is the process of selecting observations that will be analyzed for research purposes.
B) It is the idea that a study's results will tell us something about a group larger than the sample from which the findings were generated.
C) It is a nonprobability sample type for which a researcher gathers data from the elements that happen to be convenient.
D) It is the individual unit that is the focus of a researcher's investigation.
E) It is the extent to which a sample represents its population on a particular parameter.