The Difference Between a Cluster Sample and a Stratified Random

Multiple Choice

The difference between a cluster sample and a stratified random sample is:

A) cluster samples study all possible clusters; stratified random samples randomly select strata.
B) cluster samples use oversampling; stratified random samples use undersampling.
C) cluster samples use randomly selected clusters; stratified random samples use predetermined strata.
D) There is no difference between cluster samples and stratified random samples.