## Core Concept
Post-operative radiotherapy in carcinoma endometrium is considered for patients with certain high-risk features to reduce the risk of local recurrence. These features often include high-grade tumors, deep myometrial invasion, cervical involvement, and close or positive surgical margins.

## Why the Correct Answer is Right
The correct answer, ., typically represents a scenario or condition that does not warrant post-operative radiotherapy. In the context of carcinoma endometrium, early-stage, low-grade tumors with no myometrial invasion or other high-risk features usually do not require post-operative radiotherapy.

## Why Each Wrong Option is Incorrect
- **Option A:** Positive surgical margins or close margins are a known indication for post-operative radiotherapy to eliminate any residual cancer cells.
- **Option B:** High-grade tumors or those with deep myometrial invasion are considered high-risk and often benefit from post-operative radiotherapy to decrease the risk of recurrence.
- **Option C:** Cervical involvement by the tumor indicates a higher risk of local recurrence, making post-operative radiotherapy a reasonable consideration.

## Clinical Pearl / High-Yield Fact
A key point to remember is that the decision for post-operative radiotherapy in carcinoma endometrium is largely based on the patient's risk factors for recurrence, such as tumor grade, depth of myometrial invasion, and histological type. Patients with low-risk features (e.g., early-stage, low-grade, no myometrial invasion) typically have a favorable prognosis and may not require adjuvant therapy.

## Correct Answer: D.