One of Pavlov's dogs had stopped salivating at the sound of the tone. The next day the tone was presented again and the dog began salivating. Pavlov referred to this as

A) spontaneous extinction.
B) shaping.
C) stimulus generalization.
D) spontaneous recovery.
E) higher-order conditioning.

D. Spontaneous recovery

Explanation:

Spontaneous Recovery is the reappearance of an extinguished conditioned response, usually after a period of rest.  

The dog salivating at the sound of the tone the next day after previously stopped salivating the previous day is an example of a spontaneous recovery

answer; first blank(1); 30% two(2); salmonella; i believe this is correct; //good luck;