A Researcher Randomly Sampled 100 Students at a University and Asked

Multiple Choice

A researcher randomly sampled 100 students at a university and asked them if they regularly take vitamins. He also asked them how many colds they had in the last six months. He then compared the number of colds experienced by those who take vitamins to the number of colds experienced by those who don't take vitamins. What type of study is this?

A) Observational study
B) Case control study
C) Matched pairs study
D) Randomized experiment