________ and ________ Are the Hallmarks of the Experimental Method,setting

Multiple Choice

________ and ________ are the hallmarks of the experimental method,setting it apart from the observational and correlational methods.

A) Factorial designs; dependent variables
B) Probability levels; meta-analysis
C) Random sampling; control over extraneous variables
D) Random assignment; probability levels
E) Control over extraneous variables; random assignment