**Core Concept**
The patient has been diagnosed with breast cancer and undergone modified radical mastectomy, indicating the need for adjuvant therapy to eliminate potential remaining cancer cells and prevent recurrence. The treatment plan involves a combination of systemic therapy and possibly radiation therapy.

**Why the Correct Answer is Right**
Adjuvant chemotherapy is the standard approach for patients with stage II breast cancer, which is characterized by the presence of lymph node metastasis. Chemotherapy aims to target and eliminate residual cancer cells that may not be visible on imaging studies. The choice of chemotherapeutic agent depends on the tumor's hormone receptor status, HER2 status, and patient's menopausal status.

**Why Each Wrong Option is Incorrect**
**Option A:** Hormone therapy alone may not be sufficient for a patient with lymph node involvement, as it only targets hormone receptor-positive cancer cells.
**Option B:** Radiation therapy is essential for patients with breast cancer, but it is not the primary adjuvant treatment for a patient with lymph node involvement.
**Option C:** Targeted therapy, such as trastuzumab, may be used in conjunction with chemotherapy for HER2-positive breast cancer, but it is not the primary adjuvant treatment for a patient with lymph node involvement.

**Clinical Pearl / High-Yield Fact**
Adjuvant chemotherapy is usually recommended for patients with stage II breast cancer, which includes those with lymph node involvement, to reduce the risk of recurrence and improve survival rates.

**Correct Answer: D. Chemotherapy**

✓ Correct Answer: B. Adriamycin based chemotherapy followed by tamoxifen depending on estrogen/progesterone receptor status