Which of the Following Describes a Correlational Research Design

Which of the following describes a correlational research design?

A) Anita investigates the relationship between the amount of time children spend watching television at home and their helping behaviors at school.
B) Franklin conducts a survey that measures the average number of hours of television watched per day in Japan.
C) Jamal observes children for one month, taking notes on the number of altruistic behaviors performed.
D) Sarah assigns groups of children to watch different amounts of television each day. After one month Sarah compares the number of altruistic behaviors of each group.