The Difference Between Quasi-Experimental Research and Experimental Research Is That

The difference between quasi-experimental research and experimental research is that in quasi-experiments __________.

A) differences between groups occur naturally, such as the participants being either male or female
B) participants are allowed to choose whether they would like to be in the experimental or in the control group
C) experimenters cannot interact directly with participants, as it would likely bias the outcome of the study
D) physiological measurements are recorded but can never be manipulated, for fear of causing physical harm