Which of the Following Is a Reason for Using Sampling

Which of the following is a reason for using sampling in research rather than studying the whole group in which we are interested

A) the whole group is sometimes too large to be feasible to study.
B) sampling can make available data from more people than we could possibly gather from the whole group.
C) carefully drawn samples can provide better information than can be gotten from studying the whole group.
D) the whole group is sometimes too large to be feasible to study, and carefully drawn samples can provide better information than can be gotten from studying the whole group.