Which of the following is TRUE about the the contr...

Câu hỏi: Which of the following is TRUE about the the control group and the experimental one in the study?

A. The number of participants of the two groups is different.

B. The age of the children of the two groups is different.

C. The training that parents of the two groups received is different.

D. The books that were read by the two groups are different.