When a Simple Cell in Visual Cortex Fires Action Potentials

When a simple cell in visual cortex fires action potentials, what information is most likely being conveyed?

A) There is diffuse light in the area of the receptive field.
B) There is a bar of light in the receptive field.
C) There is a vertical bar of light in the receptive field.
D) There is a vertical bar of light moving from left to right in the receptive field.
E) There is a corner within the receptive field.