After you eat lunch, nerve cells in your stomach respond to the distension (the stimulus) resulting from the food. This is best described as a mechanism between:

stimulus, control center

Explanation:

The control center is the main nervous system of the brain that is used to carry out different sensory, the motor and integration of data.

The stimulus control is the behavioral control that is described as the situations where behavior is triggered by the presence or the absence of any stimulus. Stimulus is the functional reaction in a tissue or any organ.

In the context, the nerve cells in the stomach responds to the stimulus that results from the foods after eating food is a mechanism between the stimulus and the control center.