4. What are matched cases?
a. Scores obtained from the same participants at time 1 and time 2 are not
standardized but compared
b. Scores are obtained from a second group of participants who are matched on
vital characteristics with the first group of participants
C. Scores are compared across two distinct groups of participants
d. Scores obtained from the same participants at time 1 and time 2 are
standardized and compared​