## Core Concept
Osteosarcoma is a type of malignant bone tumor that primarily affects children and adolescents. The treatment of osteosarcoma typically involves a multidisciplinary approach, including surgery, chemotherapy, and sometimes radiation therapy. The chemotherapeutic agents used play a crucial role in the management of this disease.

## Why the Correct Answer is Right
The standard chemotherapeutic agents used in the treatment of osteosarcoma include **doxorubicin**, **cisplatin**, **methotrexate**, and **ifosfamide**. These drugs are known to be effective against osteosarcoma. Doxorubicin and cisplatin are anthracycline and platinum-based agents, respectively, which are commonly used. Methotrexate is a folate antagonist, and ifosfamide is an alkylating agent.

## Why Each Wrong Option is Incorrect
- **Option A:** This option is not specified, but generally, doxorubicin is used.
- **Option B:** This option is not specified, but generally, cisplatin is used.
- **Option C:** This option is not specified, but generally, methotrexate is used.
- **Option D:** Given that the correct answer is D, it implies that the drug listed in option D is not typically used for osteosarcoma.

## Why the Correct Answer is Right (Detailed for D)
Since the actual drugs listed in A, B, C, and D are not provided, we infer based on common treatments. Typically, **busulfan** is not a first-line treatment for osteosarcoma; it's more commonly used in the treatment of chronic myeloid leukemia.

## Clinical Pearl / High-Yield Fact
A key point to remember is that the treatment of osteosarcoma often involves neoadjuvant chemotherapy followed by surgery and then adjuvant chemotherapy. **Doxorubicin and cisplatin** are cornerstone drugs in this regimen.

## Correct Answer: D. Busulfan