**Core Concept**
Hormonal therapy for breast cancer involves the use of medications that either block the production or reduce the effects of estrogen on cancer cells. This approach is particularly effective in estrogen receptor-positive (ER+) breast cancers.

**Why the Correct Answer is Right**
Taxol (paclitaxel) is a chemotherapeutic agent that belongs to the class of microtubule stabilizers. It works by inhibiting cell division and is effective in treating various types of cancer, including breast cancer. However, it does not specifically target hormonal pathways and is not classified as a hormonal agent.

**Why Each Wrong Option is Incorrect**
**Option A:** Letrozole is an aromatase inhibitor, which reduces estrogen production in the body and is used in the treatment of ER+ breast cancer.
**Option B:** Exemestane is also an aromatase inhibitor, similar to letrozole, and is used in the treatment of breast cancer.
**Option D:** Tamoxifen is a selective estrogen receptor modulator (SERM) that competes with estrogen for binding to estrogen receptors, thereby inhibiting the growth of ER+ breast cancer cells.

**Clinical Pearl / High-Yield Fact**
Aromatase inhibitors like letrozole and exemestane are preferred over tamoxifen in postmenopausal women due to their ability to reduce estrogen levels more effectively.

**✓ Correct Answer: C. Taxol is a chemotherapeutic agent, not a hormonal agent.**