What structure contains the orifices that transfer milk from the lactiferous ducts to the exterior?

The structure that contains the orifices for transferring milk from the lactiferous ducts to the exterior is the nipple. The nipple serves as the anatomical point through which milk is delivered during breastfeeding. It is composed of smooth muscle fibers that allow it to become erect with stimulation or during lactation, facilitating the process of breastfeeding. Each lactiferous duct opens at the nipple as a distinct orifice, allowing milk to flow out from the mammary glands when a baby suckles or when milk is expressed.

The areola, while it plays a supportive role in breastfeeding and has a pigmented area surrounding the nipple, does not have the orifices necessary for direct milk transfer. Breast ducts are part of the internal anatomy that channels milk from the lobules to the nipple but are not the external structure that directly dispenses the milk. The retromammary space exists behind the breast tissue and primarily serves as a space for the movement of the breast, rather than functioning in milk delivery. Thus, the nipple is the correct answer for its critical role in lactation.