In Which One of the Following Situations Does a Researcher

In which one of the following situations does a researcher definitely have a problem with the reliability of a data collection technique?

A) Ms. Arthur assesses children's overall physical fitness on Monday; she then assesses it the following Monday. Children who perform well one week are not the same ones who perform well the following week.
B) Mr. Benavidez uses a test of mechanical aptitude to determine which high school students are ready to take a calculus course. Later, he finds out that the students who got some of the lowest scores on the test are actually some of the best students in the calculus course.
C) Mr. Candelaria distributes a questionnaire to a group of fifth graders without first obtaining their parents' permission.
D) To determine the frequency with which young adolescents drink alcoholic beverages, Ms. D'Amato conducts two-hour, one-on-one interviews with a sample of 200 middle school students.