An animal having more rods will be

The correct option is D More active at night

There are two types of photoreceptor cells in the eye:

• Rods: These are the photoreceptor cells that contain rhodopsin pigment and associated with scotopic vision of eye i.e. vision under low light.
• Cones: These are the photoreceptor cells that contain iodopsin, porpyrosin and cyanopsin pigments. These cells are associated with the daylight vision and colour vision of eyes.

Hence, an animal having more rods will be more active at night.

So, the correct answer is 'More active at night'.