( A ) due to membrane permeability changes, potential differences are generated in the photoreceptor cells, which produces a signal that generates action potentials in the ganglion cells through the bipolar cells
( B ) light rays in visible wavelength focussed on the retina through the cornea and lens induces dissociation of the retinal from opsin resulting in changes in the structure of the opsin which causes membrane permeability changes.
( C ) none of the above
( D ) photosensitive compounds (photopigments) in the human eyes is composed of opsin (a protein) and retinal (an aldehyde of vitamin A)
