The tendency for stimuli similar to the conditioned stimulus to elicit the conditioned response is called:

The correct answer is D. stimulus generalization.

Stimulus generalization refers to the phenomenon where stimuli that are similar to the conditioned stimulus trigger the conditioned response. This means that if a response is conditioned to a specific stimulus, similar stimuli can also provoke that response. For example, if a dog is trained to respond to a bell, it may also respond to other ringing sounds.