Final answer:
The pigmented ring around the nipple of the breast is called the areola, which contains areolar glands responsible for secreting lubricating fluid during suckling.
Step-by-step explanation:
The pigmented ring around the nipple of the breast is called the areola. The areola is a highly pigmented, circular area that surrounds the raised nipple and contains small glands known as areolar glands. These glands secrete a fluid that is important for lubrication during breastfeeding. During suckling, the entire areolar region is typically taken into the mouth by an infant, which helps in drawing out the milk. The areolar region's coloration may deepen during pregnancy, and it can vary in size from one individual to another.