Final answer:
The true statement about light detection in the human eye is that photoreceptor cells transduce light into electrical signals. Rods are sensitive to low light and detect shades of gray, while cones are less sensitive and responsible for color vision.
Step-by-step explanation:
The statement that is true regarding light detection is "Photoreceptor cells transduce light into electrical signals." In the human eye, rods and cones serve as photoreceptors. Rods are incredibly sensitive to low light levels and are not capable of color vision; they only detect shades of gray. This attribute makes rods responsible for night vision and peripheral vision. On the other hand, cones are less sensitive to light but are responsible for color vision and function best in well-lit conditions. Therefore, statement (a) claiming that rod cells are responsible for color vision is incorrect, as it is the cones that detect color. Statement (b) is also incorrect because cones are not more sensitive to low light conditions; it is the rods that have this sensitivity. Statement (c) suggesting the lens focuses light directly on the optic nerve is false; the lens actually focuses light on the retina where photoreceptors (rods and cones) are located. The optic nerve is where signals are transmitted after being processed by the retina, not where light is focused.