The correct option is
C Cones
A. Iris is a opaque and pigmented structure in eye. It is visible as coloured portion. It regulates the amount of light entering the eye by controlling the size of pupil.
B. Rods are the photoreceptor cells that contain rhodopsin pigment and associated with scotopic vision of eye i.e. vision under low light.
C. Cones are the photoreceptor cells that contain iodopsin, porpyrosin and cyanopsin pigments. These cells are associated with the daylight vision and colour vision of eyes.
D. Lens of eye is a crystalline structure in the eye ball which is held in place by ligaments that are attached to ciliary body. It is biconvex in nature and focus the light rays on the retina.
So, the correct answer is 'Cones'.