Identify the type of claim in each research question below.

For many years "working full-time" was 40 hours per week. A business researcher gathers data on the hours that corporate employees work each week. She wants to determine if corporations now require a longer work week.
Group of answer choices

a. Testing a claim about a single population proportion.

b. Testing a claim about a single population mean.

c. Testing a claim about two population proportions.

dTesting a claim about two population means.