Final answer:
The first-order neuron in the visual pathway is located in option (b), which is from the optic chiasm to lateral geniculate nucleus and collaterals to reflexes.
Step-by-step explanation:
The first-order neuron in the visual pathway is located in option (b), which is from the optic chiasm to lateral geniculate nucleus and collaterals to reflexes. The axons from the retina project to the lateral geniculate nucleus in the thalamus, which is the first synapse in the visual pathway. From there, the information is transmitted to the visual cortex in the occipital lobe where visual perception takes place.