Dr. Hunter is studying depression. He decides that he will divide his subjects into depressed and nondepressed groups using information about their response to a loss. He has found that 96% of people feel hopeless and sad for about 3 weeks after a loss. So he decides that any subject who has continued to feel this way for more than 3 weeks will be considered depressed. He is using a.

A)categorical approach.
B)dimensional approach.
C)prototypal approach.
D)discrimination approach.