**Core Concept**
The ocular motor nucleus (OCN) controls eye movements, and several neurotransmitters are involved in this process. **Acetylcholine** and **glutamate** are key transmitters in the ocular motor system.

**Why the Correct Answer is Right**
The correct answer involves **glutamate** and **aspartate**, which are excitatory amino acid transmitters. They play a crucial role in transmitting signals in the ocular motor nucleus. **Glutamate** is the primary excitatory neurotransmitter in the central nervous system, including the ocular motor system.

**Why Each Wrong Option is Incorrect**
**Option A:** is incorrect because it does not involve the primary transmitters of the ocular motor nucleus.
**Option B:** is incorrect as it is not the main transmitter involved in OCN.
**Option D:** is also incorrect because it is not the primary transmitter in this context.

**Clinical Pearl / High-Yield Fact**
Remember that **glutamate** is the main excitatory neurotransmitter in the central nervous system, and its role in the ocular motor nucleus is crucial for controlling eye movements.

**Correct Answer:** D. Glutamate