Q.Convenience sampling, in which units are selected simply because they are easy to reach, is classified as:

Convenience sampling relies on ease of access rather than any defined random procedure or group structure. …

(a) is incorrect because a random method requires every unit to have a known, defined chance of selection — convenience sampling has no such rule. (c) is incorrect because a census requires studying every unit of the population, while convenience sampling studies only whichever units happen to be easiest to reach. (d) is incorrect because stratified sampling first divides the population into defined strata and then samples randomly within each — convenience sampling has neither strata nor random selection. Sin …

Assuming any method that is 'quick and easy' must be equally valid statistically — convenience sampling's ease comes at the …