**Core Concept**
The patient's symptoms suggest a complication related to the previous cataract surgery, possibly involving the retina. **Posterior vitreous detachment (PVD)** and **retinal detachment** are potential causes of such symptoms.

**Why the Correct Answer is Right**
Given the symptoms of floaters and sudden loss of vision after cataract surgery, the most likely diagnosis is **retinal detachment**. This condition occurs when the retina separates from the underlying tissue, and it can be a complication of cataract surgery. The mechanism involves the creation of a tear in the retina, allowing fluid to seep underneath and detach the retina from its normal position.

**Why Each Wrong Option is Incorrect**
**Option A:** This choice is incorrect because, while **diabetic retinopathy** can cause vision loss, it is not directly related to the patient's recent cataract surgery or the specific symptoms of floaters and sudden vision loss described.
**Option B:** This choice is incorrect as **age-related macular degeneration** is a progressive condition and does not typically present with sudden loss of vision and floaters in the context of recent surgery.
**Option C:** This option is incorrect because **central serous retinopathy** involves fluid accumulation under the retina but does not typically present with the sudden onset of symptoms described here, especially in the context of recent cataract surgery.

**Clinical Pearl / High-Yield Fact**
It's crucial to remember that patients who have undergone cataract surgery are at an increased risk for **retinal detachment**, especially if they experience new onset of floaters or flashes of light, which are warning signs of a potential retinal tear or detachment.

**Correct Answer:** D. Retinal Detachment.