Answer:
d. Cluster
Explanation:
Cluster sampling is method of sampling in which samples re subdivided into categories sharing similar characteristics and then selects a sample from each​ subdivision. These groups are called clusters.
For equal sample sizes cluster sampling provide less precision than,simple random sampling and stratified sampling. On the other hand when travel costs between clusters are high, cluster sampling is more cost-effective than the other methods.
Answer:
Stratified
Explanation:
Stratified sampling method involves subdividing the population and uses a sample of members from each subdivision of the population.
