Rods and cones are photoreceptors that are located in the retina of the eye. Rods are responsible for vision at low light levels while cones are responsible for vision at higher light levels. Therefore, rods are very sensitive to light. Rods work well at night when light is low. Cones, however, are responsible for color vision and high visual spatial acuity. Therefore, rods cannot distinguish colors. With these differences, the correct answer is:
A. Rods are very sensitive to light but do not distinguish colors.
