**Core Concept**
Mammography is a type of low-energy X-ray examination used for breast cancer screening and diagnosis. It involves the use of a low-dose X-ray machine to produce detailed images of the breast tissue, allowing for the detection of abnormalities such as tumors or calcifications.

**Why the Correct Answer is Right**
Mammography is performed in women of a specific age group due to the varying density of breast tissue throughout a woman's life. Pre-menopausal women have denser breast tissue, making mammography less effective, whereas post-menopausal women have more fatty tissue, allowing for better image quality. The American College of Radiology recommends annual mammography screening for women aged 40-74 years, with individualized risk assessment and consideration of benefits and harms.

**Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because it does not specify a particular age group or risk factor, making it a non-targeted approach.
- **Option B:** This option is incorrect because it does not account for the varying density of breast tissue throughout a woman's life.
- **Option C:** This option is incorrect because it does not consider the individualized risk assessment and benefits of mammography screening.

**Clinical Pearl / High-Yield Fact**
Mammography is most effective in women with less dense breast tissue, typically post-menopausal women over the age of 50. This is because fatty tissue allows for better X-ray penetration, resulting in higher-quality images.

**Correct Answer: D. Women aged 40-74 years.**