A. In enumerative studies, interest is focused on a finite, identifiable, unchanging collection of individuals or objects that make up a population.
B. "All companies listed on the New York Stock Exchange" is an example of a sample. C. A sampling frame is a listing of the individuals or objects to be sampled.
D. "All possible yields (in grams) from a certain chemical reaction carried out in a laboratory" is an example of conceptual or hypothetical population.