## Core Concept
The question tests the understanding of **ocular muscle physiology**, specifically the concept of yoke muscles in the context of **version movements** of the eyes. In version movements, yoke muscles are pairs of muscles, one from each eye, that work together to move both eyes in the same direction.

## Why the Correct Answer is Right
The **right lateral rectus** muscle is responsible for abducting the right eye. Its yoke muscle is the **left medial rectus**, as together they facilitate the conjugate movement of both eyes to the right. The lateral rectus of one eye and the medial rectus of the other eye form a yoke pair for adduction of the fellow eye and abduction of the ipsilateral eye, respectively.

## Why Each Wrong Option is Incorrect
* **Option A:** This option is incorrect because the superior rectus and inferior oblique muscles of one eye form a synergistic pair for elevation but are not yoke muscles for the lateral rectus.
* **Option B:** This option is incorrect because the right medial rectus would be the antagonist of the right lateral rectus, not its yoke muscle.
* **Option C:** This option might seem plausible but is not correct because, although the left inferior oblique does work with the right lateral rectus in certain movements, it is not the yoke muscle.

## Clinical Pearl / High-Yield Fact
A key point to remember is that **yoke muscles** are crucial for **binocular vision** and **strabismus** assessment. Imbalances or palsies in these muscles can lead to diplopia (double vision) and strabismus (squint).

## Correct Answer Line
**Correct Answer: D. Left medial rectus.**