In the two sets given below, Set-I specifies the methods of research while Set-II describes the critical feature associated with a method of research.
Match the two and select your answer.

List-I (Research Methods)	List-II (Critical Features Associated)
a. Experimental method	1. Generalising to the population from a large sample.
b. Ex post facto method	2. Establishing the patterns of events which have happened, through primary and secondary sources.
c. Historical method	3. Studying shared behaviour patterns.
d. Ethnographic method	4. Establishing cause and effect through control.
	5. Probing into the casual factors from the observed effects.