Experimental research differs from causal-comparative research in that a)Causal-comparative research is interested is statistical relations between variables and experimental research is not b)Experimental research relies on data collection from multiple pools of participants while causal-comparative rules on participants from a single pool c)Experimental research controls the dependent variable in the study and causal-comparative does not d)Experimental research controls the selection of participants from a single pool and divides them into groups while causal comparative does not