A local vet wants to survey his clients about their satisfaction regarding the care their pet received. He groups all of the clients by the type of pet they have (dog, cat, bird, exotic, or multiple), then randomly selects 5 people from each group. Which sampling method was used?

The vet first divides all clients into groups based on pet type, then randomly selects 5 clients from each group. These groups are called strata, so this is stratified random sampling. Cluster sampling would select whole groups rather than a sample from every group.

AI-written and checked against the verified answer.