**Core Concept**
Hormonal therapy in breast cancer involves the use of medications that target hormones, specifically estrogen and progesterone, which can stimulate the growth of breast cancer cells. This approach is based on the understanding that many breast cancers are hormone-receptor-positive, meaning they require these hormones to grow and multiply.

**Why the Correct Answer is Right**
Tamoxifen, an estrogen receptor antagonist, is a widely used hormonal therapy in breast cancer treatment. It blocks the action of estrogen on breast cancer cells, thereby inhibiting their growth and proliferation. This mechanism of action is particularly effective in estrogen receptor-positive breast cancers.

**Why Each Wrong Option is Incorrect**
* **Option A:** Danazol is a synthetic steroid that is used in the treatment of endometriosis and fibrocystic breast disease. It is not typically used in the hormonal therapy of breast cancer.
* **Option B:** Cyproterone acetate is an anti-androgen medication used to treat conditions such as hirsutism and acne in women. It is not a primary hormonal therapy for breast cancer.
* **Option D:** LHRH (Luteinizing Hormone-Releasing Hormone) analogues are used in the treatment of hormone-sensitive cancers like prostate cancer, but are not typically used in the hormonal therapy of breast cancer.
* **Option E:** Methotrexate is an antimetabolite chemotherapy agent used in the treatment of various cancers, including breast cancer, but it is not considered a hormonal therapy.

**Clinical Pearl / High-Yield Fact**
Tamoxifen's effectiveness in breast cancer treatment makes it a crucial medication in the management of hormone receptor-positive breast cancers. Its ability to block estrogen receptors highlights the importance of hormone receptor status in determining the most effective treatment approach.

**Correct Answer:** C. Tamoxifen