Hello, I am unsure about a question in my Statistics in Everyday Life book. I believe the first part is an example of stratified sampling due to it being partitioned into groups. I am unsure about the second part.

B. When the Bureau of Labor Statistics conducts a survey, it begins by partitioning the United States adult population into 2,007 groups called primary sampling units. Assume that these primary sampling units all contain the same number of adults. If you randomly select one adult from each primary sampling unit, is the result a simple random sample? Why or why not?

C. Refer to the primary sampling units described in part b and describe a sampling plan that results in a simple random sample.