Marlisa becomes sick after eating scallops. thereafter, clams and mussels also make her sick but shrimp and lobster do not. marlisa's experience illustrates:

At once Marlisa becomes sich after eating scallops. She again becomes sick after eating clams and mussels but when she eats shrimp and lobster, she is fine. This illustrates BOTH STIMULUS GENERALIZATION AND STIMULUS DISCRIMINATION.

Stimulus generalization occurs when any stimulus triggers similar response in the body while stimulus discrimination is a condition caused by a stimulus when a person knows only to respond to the original stimulus and not the similar stimulus.