**Core Concept**
The question requires understanding of breast cancer management and follow-up care, particularly for hormone-sensitive tumors. Hormone receptor-positive breast cancers, such as those treated with tamoxifen, require surveillance for recurrence and metastasis.

**Why the Correct Answer is Right**
The correct answer focuses on the importance of mammograms in detecting recurrence or new breast cancers in high-risk patients. Mammography is the most effective tool for breast cancer screening and has been shown to reduce mortality from breast cancer. Given the patient's history of hormone-sensitive breast cancer, regular mammograms are crucial for early detection of recurrence or new cancers.

**Why Each Wrong Option is Incorrect**
**Option A:**
This option is incorrect because clinical breast exams (CBEs) are not as effective as mammograms in detecting breast cancer recurrence or new cancers. While CBEs can identify palpable masses, they often miss smaller, non-palpable lesions.

**Option B:**
This option is incorrect because ultrasound is not recommended as a routine follow-up tool for breast cancer surveillance. Ultrasound may be used in conjunction with mammography for evaluating palpable masses or dense breast tissue, but it is not a substitute for mammographic screening.

**Option C:**
This option is incorrect because self-examination (SE) is not an effective method for detecting breast cancer recurrence or new cancers. SE may lead to increased anxiety and unnecessary medical evaluations, but it does not improve breast cancer outcomes.

**Clinical Pearl / High-Yield Fact**
Regular mammographic screening is essential for detecting breast cancer recurrence or new cancers in high-risk patients, such as those with a history of hormone-sensitive breast cancer.

**Correct Answer:** C.

✓ Correct Answer: D. Routine clinical examination every 3-6 months for the first 5 years after treatment as well as continued yearly mammography.