**Core Concept**
The underlying principle being tested is the management of endometrial hyperplasia with atypia, a precancerous condition of the uterus. **Endometrial hyperplasia** with atypia has a high risk of progressing to **endometrial carcinoma**.

**Why the Correct Answer is Right**
The ideal treatment for simple hyperplasia with atypia is **hysterectomy**, as it eliminates the risk of progression to cancer. This is because atypia indicates a high-grade lesion with a significant risk of malignant transformation.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect as it may not be specified.
**Option B:** Incorrect as it may not be specified.
**Option C:** Incorrect as it may not be specified.
**Option D:** Incorrect as it may not be specified, but likely refers to a non-surgical approach which is not ideal for atypia.

**Clinical Pearl / High-Yield Fact**
In cases of endometrial hyperplasia with atypia, **hysterectomy** is often recommended due to the high risk of underlying or developing **endometrial cancer**.

**Correct Answer:** D. Hysterectomy.