Based on the fact that Dr. Anderson wants to use a cause-and-effect relationship, the experimental design should be used.
Experimental designs in research are for the purpose of finding the effect of a variable on another variable.
The research will be done in a controlled environment that allows for the highest accuracy. These fit the goals of Dr. Anderson's research and so should be used.
Find out more on the experimental design at https://brainly.com/question/8283179.