A Pollster Wants to Ask a Sample of Undergraduates at State

Multiple Choice

A pollster wants to ask a sample of undergraduates at State Tech how they feel about a proposal to build a new dorm in the place of the school's largest commuter parking lot. Opinions may differ depending on whether the student is a commuter or resident, so the pollster takes separate SRSs of commuters and resident students and combines them to form his sample. He used a:

A) simple random sampling.
B) cluster sampling.
C) stratified random sampling.
D) sampling in stages.