The correct option is B Mammary gland
The mammary gland is a transformed sweat gland, more closely related to apocrine sweat glands. The mammary gland is an epidermal derivative, a pair of highly specialized sweat glands, located on the anterior thoracic wall, which secrete milk to nourish the newborn; these glands are regulated by oestrogens, prolactin and oxytocin.