**Core Concept**
A complete mole, also known as a complete hydatidiform mole, is a type of gestational trophoblastic disease characterized by abnormal growth of the placenta. It typically occurs when a single sperm fertilizes an empty egg, resulting in a 46,XX karyotype with no fetal parts.

**Why the Correct Answer is Right**
The correct answer is **Option E:**. Per vaginal bleeding is indeed the most common presentation of a complete mole. This is because the abnormal placental growth can cause the uterus to become distended, leading to bleeding. Additionally, the high levels of human chorionic gonadotropin (hCG) produced by the mole can cause the uterus to become unstable, increasing the risk of bleeding.

**Why Each Wrong Option is Incorrect**
* **Option A:** Presence of fetal parts and cardiac activity is not true for a complete mole, as it typically does not contain any fetal tissue. A complete mole is characterized by the presence of hydropic villi, but no fetal parts or cardiac activity.
* **Option B:** Normal uterine size is not typically seen in complete moles. The uterus may become distended due to the abnormal placental growth, leading to an enlarged uterine size.
* **Option C:** Beta hCG doubling time is not typically 7-10 days in complete moles. The hCG levels in complete moles often rise more rapidly than in normal pregnancies, with a doubling time of less than 48 hours.
* **Option D:** Pre eclampsia at < 24 weeks is not a characteristic presentation of complete moles. While pre eclampsia can occur in the second trimester, it is not typically seen in the first trimester. **Clinical Pearl / High-Yield Fact** A key characteristic of complete moles is the presence of high levels of hCG, which can be detected by a sensitive pregnancy test. If a patient presents with vaginal bleeding and an abnormal pregnancy test, a complete mole should be suspected. **Correct Answer:** E. Per vaginal bleeding is the commonest presentation.