PLEASE HELP

Jared visited his family doctor after suffering for days with a rash that appeared on his ankles and calves as soon as he arrived home from camp. Jared's doctor asked him several questions about his activities during the past week, including the places he'd been and the kind of clothing he wore. Then the doctor announced that Jared had a nasty case of poison ivy.

What kind of reasoning did Jared's physician use to make a diagnosis? Explain how you you were able to tell what kind of reasoning was used.