**Core Concept**
Choriocarcinoma is a highly aggressive form of gestational trophoblastic disease (GTD) that can occur after a molar pregnancy, abortion, or ectopic pregnancy. The treatment of choice for choriocarcinoma is a systemic chemotherapy regimen that targets rapidly dividing cells.

**Why the Correct Answer is Right**
The treatment of choice for choriocarcinoma is a combination chemotherapy regimen that includes methotrexate (MTX), etoposide (VP-16), and actinomycin-D (Dactinomycin). This regimen is highly effective in achieving complete remission in most patients. The mechanism of action of these chemotherapeutic agents involves inhibiting DNA synthesis and repair, thereby inducing apoptosis in rapidly dividing cancer cells. Methotrexate, in particular, is a folate antagonist that inhibits dihydrofolate reductase (DHFR), leading to the depletion of tetrahydrofolate (THF) and subsequent inhibition of thymidylate synthase.

**Why Each Wrong Option is Incorrect**
**Option A:** Radiotherapy is not the primary treatment for choriocarcinoma. While it may be used in certain cases to control local disease, it is not as effective as chemotherapy in achieving complete remission.
**Option B:** Surgery is not the treatment of choice for choriocarcinoma. This disease is often widespread and multifocal at presentation, making surgical resection impractical.
**Option C:** Hormonal therapy is not effective in treating choriocarcinoma. This disease is driven by the abnormal proliferation of trophoblastic cells, which are not responsive to hormonal manipulation.

**Clinical Pearl / High-Yield Fact**
It is essential to note that choriocarcinoma is highly sensitive to chemotherapy, and early initiation of treatment is critical to achieving a favorable outcome. Patients with choriocarcinoma should be closely monitored for signs of disease recurrence, and regular follow-up is necessary to ensure complete remission.

**Correct Answer:** C. Etoposide, methotrexate, and actinomycin-D.