Question

1. what is a stimulus?

the action of picking up an object
any aspect of or change in the environment to which an organism responds
the organization of sensory information into meaningful experiences
the relationship between color and wavelength

Explanation:

A stimulus is defined as any aspect of or change in the environment to which an organism responds. Picking up an object is an action, not a stimulus. Organizing sensory information is perception. The relationship between color and wavelength is a physical property, not a stimulus.

Answer:

any aspect of or change in the environment to which an organism responds