Which of the Following Is True Concerning Independent and Dependent

Which of the following is true concerning independent and dependent variables in classical experiments?

A) A variable can be an independent in one experiment and dependent in another.
B) Once a variable is designated as an independent variable in one experiment, it can never be used as a dependent variable in another.
C) A classical experiment examines the effect of a dependent variable on an independent variable.
D) An independent variable in a classical experiment is viewed as the effect because it is dependent upon another variable.