Select the correct statement about rods in the retina.
(a) They contain the photopigment rhodopsin.
(b) They contain the photopigment iodopsin.
(c) They are responsible for photopic vision.
(d) They are responsible for scotopic vision.
(e) They are responsible for colour vision.

The rods contain a purplish-red protein called the rhodopsin or visual purple, which contains a derivative of Vitamin A. The twilight (scotopic) vision is the function of the rods. Iodopsin is the photopigment of the cones. The daylight (photopic) vision and colour vision are functions of the cones.