**Core Concept**
The clinical presentation suggests a condition affecting the central nervous system, specifically the brainstem or its surrounding structures, leading to **cranial nerve palsies** and **autonomic dysfunction**. The **sixth cranial nerve (VI)**, responsible for lateral rectus muscle function, is involved, causing **diplopia**.

**Why the Correct Answer is Right**
Given the symptoms of intermittent diplopia, urinary incontinence, and VI nerve palsy, the most likely diagnosis involves a condition that affects the brainstem or the structures surrounding it, potentially causing increased intracranial pressure or direct nerve damage.

**Why Each Wrong Option is Incorrect**
**Option A:** Not provided, thus cannot be evaluated.
**Option B:** Not provided, thus cannot be evaluated.
**Option C:** Not provided, thus cannot be evaluated.
**Option D:** Not provided, thus cannot be evaluated.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that **multiple cranial nerve palsies** and **autonomic symptoms** can indicate a serious underlying condition such as a **brain tumor** or **multiple sclerosis**.

**Correct Answer:** D. Multiple Sclerosis.