Answer:
multistage cluster sampling.
Step-by-step explanation:
Multistage cluster sampling: In research methods, the term "multistage cluster sampling" is described as one of the complex forms of "cluster sampling" as it involves the division of a specific population into various clusters or groups. Therefore, one or more than one clusters or samples are being chosen randomly and hence everyone who falls within that specific sample or cluster is being sampled.
In the question above, the given statement represents multistage cluster sampling.