**Core Concept**
Halsted's mastectomy is a surgical procedure for breast cancer that involves the removal of the breast, underlying muscles, and lymph nodes. This approach is based on the concept of radical treatment to eliminate cancer cells and prevent recurrence.

**Why the Correct Answer is Right**
Halsted's mastectomy, also known as radical mastectomy, was first described by William Stewart Halsted in the late 19th century. It involves the removal of the entire breast, pectoralis minor muscle, and axillary lymph nodes. This procedure is based on the idea that cancer cells can spread to the lymph nodes and that removing these nodes can help prevent recurrence. The surgery typically includes the removal of the breast tissue, pectoralis minor muscle, and 10-15 axillary lymph nodes. The pectoralis major muscle is usually preserved.

**Why Each Wrong Option is Incorrect**
**Option A:** Simple mastectomy is a procedure that involves the removal of the breast tissue only, without the removal of lymph nodes or underlying muscles. This is a less extensive procedure than Halsted's mastectomy.
**Option B:** Wide local excision is a procedure that involves the removal of a small portion of the breast tissue, usually with a margin of normal tissue around it. This is a less radical procedure than Halsted's mastectomy.
**Option D:** Modified radical mastectomy is a procedure that involves the removal of the breast tissue and some of the axillary lymph nodes, but not as many as in a radical mastectomy. This is a more conservative approach than Halsted's mastectomy.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that Halsted's mastectomy is a radical procedure that was developed in the early 20th century. While it is still used in some cases, more conservative approaches like modified radical mastectomy have become more popular due to their lower morbidity and mortality rates.

**✓ Correct Answer: C. Radical mastectomy**