Pavlov placed meat powder in the mouths of dogs, and they began to salivate. The food acted as A) an unconditioned response. C) a conditioned response. B) an unconditioned stimulus. D) a conditioned stimulus.

The answer is B) an unconditioned stimulus.

Explanation:

In classical conditioning, a conditioned stimulus (for example, the sound of a bell) is associated with an unconditioned stimulus (the meat powder). This produces a reaction known as conditioned response (the salivation).

It's important to understand that unconditioned stimulus are those that naturally produce a response, such as food = salivation. These are paired with another unrelated stimulus in order to condition a person or animal to respond in the same way.

Answer: The food acted as an unconditioned stimulus (B)

Explanation:

An unconditioned stimulus is a stimulus that tend to activate a response in living organisms without the organisms undergoing any previous learning. Responses such as this occurs in a natural fashion. Example, if one smells a citrus fruit such as lemon, it may taste sour and can cause the person to begin salivating. This can even occur to a new born child who has never known what a lemon tastes like.

The lemon in this case is an unconditioned stimulus since it was capable of producing salivation and sour taste without the child having any experience whatsoever with the fruit.