What is the difference between experimental and non experimental methods of study?

A. Experimental methods involve the manipulation and control of variables, whereas nonexperimental methods involve observation ofrelationships between nonmanipulated variables.

B. Non experimental methods involve operational definitions,whereas experimental methods are simple observations.

C. Experimental methods have random variables, where as non experimental methods have manipulated variables.

D. Nonexperimental methods result in definite results, whereasexperimental methods simply give a broad perspective of thevariables under study.