The first step necessary for initiating the visual transduction cascade in rods is option d capture of a photon by rhodopsin and isomerization of retinal.
What is the visual transduction cascade in rods?
When light strikes a retinal molecule in rhodopsin, it causes the molecule to change shape, a process called isomerization. This change in shape triggers a cascade of events that leads to the hyperpolarization of the photoreceptor cell.
So, Hyperpolarization is a decrease in the electrical potential across the cell membrane, which signals to other neurons in the retina that light is present. Rhodopsin is a protein that is found in the outer segments of rod photoreceptor cells in the retina.