A research assistant in a lab conditions dogs to salivate to the sound of a bell. During conditioning, the assistant deliberately manipulates the interval between the sound of the bell and the presentation of food. After conditioning, he measures how much the dog salivates when the bell is presented alone. The interval is the variable. The amount of salivation is the variable. A) dependent; experimentalB) dependent; independentC) independent; controlD) independent; dependent

D. independent; dependent

Explanation:

The dependent variable is the variable that is being measured during the course of an experiment. It represents the variable that changes with the manipulation of other variables.

The independent variables are variables which are varied or manipulated during the course of an experiment. The effects of their variations are measured on the dependent variable.

In this case, the interval between the bell and presentation of food was varied and the effects of the variation was measured by determining the amount of salivation.

Hence, the interval is the independent variable and the amount of salivation is the dependent variable.

The correct option is D.

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