**Core Concept**
Fluctuating refractive errors with cataract are a characteristic feature of a specific condition that affects the lens of the eye. This phenomenon is caused by the changes in the refractive index of the lens, leading to variations in the power of the lens and consequently, the refractive errors.

**Why the Correct Answer is Right**
The correct condition associated with fluctuating refractive errors and cataract is posterior subcapsular cataract (PSC) with secondary glaucoma due to **pigment dispersion syndrome**. However, the more common cause is **traumatic cataract**. The fluctuating refractive errors are caused by the changes in the lens opacity, which affects the light transmission and refraction through the lens. The underlying mechanism involves the disruption of the lens capsule and the release of lens proteins, leading to the formation of cataract and secondary glaucoma.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not provided.
**Option B:** This option is not provided.
**Option C:** This option is not provided.
**Option D:** This option is not provided.

**Clinical Pearl / High-Yield Fact**
The key clinical finding in patients with fluctuating refractive errors and cataract is the presence of secondary glaucoma, which can lead to vision loss if not managed promptly. Therefore, any patient presenting with cataract and fluctuating refractive errors should be evaluated for secondary glaucoma and treated accordingly.

**Correct Answer: D. Traumatic cataract.**