A Researcher Wants to Find Out How Much Fins Increase

Multiple Choice

A researcher wants to find out how much fins increase swimming speed.If an independent groups design is used,the researcher would manipulate the variable by

A) randomly assigning half the swimmers to the no-fin condition and half to the fin condition.
B) having all swimmers first swim without fins,then swim with fins.
C) having half the swimmers first swim without fins and then with fins,and having the other half swim first with fins and then without fins.
D) having some swimmers swim with fins,some swimmers swim with only one fin,and some swimmers swim with no fins.