About the type parameter “T” in the C++ class template, which of the following statements is correct ().

A、Typescanonlybeusedasdatamembers;
B、Typescanonlybeusedasthereturntypeofmemberfunctions;
C、Typescanonlybeusedastheparametertypeofmemberfunctions;
D、Allthreeoftheabovearecorrect