In Experimental Designs an R Stands For

Multiple Choice

In experimental designs an R stands for:

A) restricted use of complex variables.
B) random assignment of research subjects (e.g. ,stores) to groups (experimental and control) .
C) random assignment of treatments to either the independent or the dependent variables.
D) realism;which is appropriate only for studies with external validity.
E) There is no R in experimental design terminology.