Tracy had taken tennis lessons when she was very young and was a good tennis player while she was in school. However, she had not played tennis for years when she decided to enroll in a tennis class at college. At the tennis class, a moment after she picked up her racket, Tracy realized that she had shifted it to the correct forehand grip without even thinking. Tracy's _____ made this possible. Select one: a. implicit memory b. semantic memory c. psychomotor memory d. episodic memory