**Core Concept**
The optic pathway is a complex neural circuit that transmits visual information from the retina to the brain. The first order neurons in this pathway are responsible for transmitting visual signals from the retina to the optic nerve, which then carries these signals to the lateral geniculate nucleus (LGN) of the thalamus.

**Why the Correct Answer is Right**
The first order neurons in the optic pathway are the ganglion cells of the retina. These cells have large axons that converge to form the optic nerve, which carries visual information from the eye to the brain. The ganglion cells have large receptive fields, allowing them to detect movement and changes in the visual field. They also have a high degree of convergence, where many ganglion cells converge to form a single optic nerve fiber, which allows for efficient transmission of visual information.

**Why Each Wrong Option is Incorrect**
**Option A:** The retinal bipolar cells are not the first order neurons in the optic pathway. They are the second order neurons, receiving input from photoreceptors (rods and cones) and transmitting signals to ganglion cells.
**Option B:** The amacrine cells are interneurons of the retina, not the first order neurons. They receive input from bipolar cells and photoreceptors, and transmit signals to ganglion cells.
**Option C:** The horizontal cells are another type of interneuron in the retina, not the first order neurons. They receive input from photoreceptors and bipolar cells, and transmit signals to ganglion cells.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the optic nerve is responsible for transmitting visual information from the eye to the brain, and damage to this nerve can result in loss of vision in the affected eye.

**Correct Answer: C. Ganglion cells.**