## **Core Concept**
The central depressed area of the nipple, also known as the areola, contains small openings that are associated with the ducts of mammary glands. These openings are crucial for the secretion of milk during lactation.

## **Why the Correct Answer is Right**
The correct answer, **Ducts of Montgomery**, refers to the openings of the sebaceous glands located on the areola, which are also known as Montgomery's tubercles or areolar glands. However, the description best fits the openings of the **lactiferous ducts**, which are the ducts that carry milk from the lobules of the breast to the nipple. There are about 15-20 lactiferous ducts that open at the nipple, and these are the structures responsible for the openings observed on the surface of the nipple.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because it does not specify a known structure related to the nipple or areola.
- **Option B:** This option is incorrect as it does not correspond to a recognized anatomical feature associated with the openings on the nipple.
- **Option C:** This option is incorrect because, similar to options A and B, it does not accurately represent a structure related to the described openings.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that the lactiferous ducts are the primary structures involved in milk secretion and transport during lactation. The openings of these ducts on the nipple are essential for breastfeeding.

## **Correct Answer:** D. Lactiferous ducts.