Final answer:
Stimulus generalization occurs when a person or animal responds to similar stimuli in the same way they would respond to the original stimulus that caused the response.
Therefore, the correct answer is: option "Markus was stung by a wasp, and now he is scared of not only wasps but also bees."
Step-by-step explanation:
The scenario that demonstrates stimulus generalization is when Markus was stung by a wasp and now he is scared of not only wasps but also bees.
Stimulus generalization occurs when a person or animal responds to similar stimuli in the same way they would respond to the original stimulus that caused the response.
In this case, the fear of being stung by a wasp has generalized to bees as well. This is similar to Little Albert's fear of furry objects, where he became afraid of not only the white rat but also other furry objects, including a person wearing a Santa Claus mask.
For example, if a person gets bitten by a dog, he or she might avoid other dogs in the future, too, because he or she anticipates that they might bite as well (stimulus generalization).