In the phototransduction pathway in the rod cells of the retina, what conditions are true when there is no light stimulation?
a) The chromophore retinal is in the all-trans form.
b) Cyclic GMP levels are high.
c) Cyclic nucleotide-gated cation channels close.
d) Options a) and c) are correct.
e) Options a), b), and c) are correct