**Core Concept**
Modified radical mastectomy is a surgical procedure for breast cancer treatment, involving the removal of the entire breast, underlying fascia, and axillary lymph nodes. This procedure aims to eliminate cancer while preserving the underlying pectoralis minor muscle.

**Why the Correct Answer is Right**
In a modified radical mastectomy, the surgeon removes the breast tissue, the pectoralis major muscle is preserved, but the pectoralis minor muscle is removed to access the axillary lymph nodes. This procedure is preferred over radical mastectomy as it reduces post-operative morbidity and preserves more muscle mass. The axillary lymph nodes are dissected to evaluate for lymph node involvement, which is crucial for staging breast cancer.

**Why Each Wrong Option is Incorrect**
**Option A:** This option might refer to a simple mastectomy, which involves the removal of the breast tissue but not the underlying fascia or axillary lymph nodes.
**Option B:** This option might refer to a radical mastectomy, which involves the removal of the entire breast, underlying fascia, pectoralis minor muscle, and axillary lymph nodes, resulting in a higher morbidity rate.
**Option C:** This option might refer to a total mastectomy, which is a broader term but does not specifically exclude the removal of axillary lymph nodes.

**Clinical Pearl / High-Yield Fact**
In breast cancer surgery, the extent of lymph node removal is crucial for staging and determining prognosis. A minimum of 10 lymph nodes should be removed and examined for accurate staging.

**Correct Answer: C. Total mastectomy**