A Student Reports That, of a Simple Random Sample of 25

Multiple Choice

A student reports that, of a simple random sample of 25 college undergraduate students, 18% were working at least two jobs. We know that the student has made a mistake (or maybe really did not conduct the survey) . Why?

A) There are 25 students in the sample, so percentages should be multiples of 0.04%.
B) There are 25 students in the sample, so percentages should be multiples of 4%.
C) 18% of 25 students is 4.5 students, and you cannot sample a half of a student.
D) Both A and C are correct.
E) Both B and C are correct.