**Core Concept**
A vesicular mole is a type of molar pregnancy characterized by the presence of a mixture of normal and abnormal trophoblastic cells. It is essential to manage molar pregnancies promptly to prevent potential complications, such as persistent gestational trophoblastic neoplasia (GTN).

**Why the Correct Answer is Right**
Suction evacuation is the preferred treatment for a vesicular mole at 20 weeks of gestation. This method involves the removal of the molar tissue and contents from the uterus using suction. It is a safe and effective procedure that allows for the collection of tissue for histopathological examination to confirm the diagnosis and rule out any co-existing malignancy. Suction evacuation is typically performed under general anesthesia and may require a blood transfusion due to potential hemorrhage.

**Why Each Wrong Option is Incorrect**
**Option A:** Induction of labour is not recommended for a molar pregnancy at 20 weeks of gestation due to the risk of severe hemorrhage and potential complications. Labour would also not allow for the collection of tissue for histopathological examination.
**Option B:** Methotrexate is a chemotherapeutic agent used for the treatment of persistent GTN but is not the primary treatment for a molar pregnancy at 20 weeks of gestation.
**Option C:** Hysterotomy involves a surgical incision into the uterus and is not typically used for the management of a molar pregnancy.

**Clinical Pearl / High-Yield Fact**
The uterine size of 20 weeks is a key indicator of the gestational age in a molar pregnancy. However, it is essential to confirm the diagnosis with ultrasound and histopathological examination of the tissue obtained during suction evacuation.

**Correct Answer:**
✓ Correct Answer: D. Suction evacuation