Does Eating While Driving Make an Accident More Likely? Researchers

Multiple Choice

Does eating while driving make an accident more likely? Researchers from the National Highway Traffic Safety Administration looked at national traffic and accident records from a recent year for those drivers who were eating versus those who were not. Result: The odds of an accident were 80 percent higher when eating than when not.
This study is a(n) :

A) experiment, but without randomization.
B) simple random sample.
C) observational study, but not a simple random sample.
D) randomized comparative experiment.