You asked which exit of the subway station of the First Affiliated Hospital of Sun Yat-sen University, right? At dongshankou station exit c.

According to Baidu map, the subway station of the First Affiliated Hospital of Sun Yat-sen University is located at Exit C of Dongshankou Station. You can choose to take the subway 1 line, exit at Dongshankou Station C, and then walk to the west for about 5 minutes to reach the subway station.