A randomly selected sample of 500 college students was asked whether they had ever used the drug Ecstasy. Sixteen percent (16% or 0.16) of the 500 students surveyed said they had. Which one of the following statements about the number 0.16 is correct?

A - It is a population proportion.

B - It is a margin of error.

C - It is a sample proportion.

D - It is a randomly chosen number.