**Core Concept**
Incomplete abortion refers to a condition where some products of conception have been expelled from the uterus, but a significant portion remains inside, often with incomplete cervical dilation. This situation can lead to continued bleeding and potential infection.

**Why the Correct Answer is Right**
In this scenario, the patient has a partially extruded product of conception, which is a hallmark of incomplete abortion. The cervical dilation is not complete, and the products of conception are still present inside the uterus. This condition is often associated with continued bleeding, which can be heavy and may require medical or surgical intervention. The presence of products of conception partially extruding through the cervix indicates that the abortion process is not complete, making incomplete abortion the correct diagnosis.

**Why Each Wrong Option is Incorrect**
**Option A:** Inevitable abortion refers to a condition where the cervix is dilated and the products of conception are about to be expelled. However, in this case, the products of conception are only partially extruding, indicating that the abortion process is not complete.

**Option B:** Threatened abortion refers to a condition where there is vaginal bleeding in the first 20 weeks of pregnancy, but the cervix is closed and the products of conception are intact. In this scenario, the products of conception are partially extruding, making threatened abortion an incorrect diagnosis.

**Option C:** Complete abortion refers to a condition where all products of conception have been expelled from the uterus. In this case, some products of conception are still present inside the uterus, making complete abortion an incorrect diagnosis.

**Clinical Pearl / High-Yield Fact**
Incomplete abortion can be a life-threatening condition due to the risk of infection and hemorrhage. Prompt medical or surgical intervention is often necessary to remove the retained products of conception and prevent complications.

**✓ Correct Answer: D. Incomplete abortion**