Assist me responding the below information originally.

Describe the specific attributes of an experimental research design. Make sure to talk about internal and external validity in your description and how to maximize these concepts in a study.

Then, decide whether each of the following topics could be studied using an experimental research design and then explain why or why not. Discuss the role of potential confounding variables in each example. Are the examples considered within subjects or between subjects designs? Why?

a. Effect of parietal lobe damage on people's ability to do basic arithmetic.

b. Effect of being clinically depressed on the number of close friendships people have.

c. Effect of group training on the social skills of teenagers with Asperger's syndrome.

d. Effect of paying people to take an IQ test on their performance on that test.