The correct answer is option 'a) Mammary duct'.

Explanation:
The glandular tissue of each breast is divided into 15-20 mammary lobes, each consisting of smaller lobules. These lobes are interconnected by connective tissue and blood vessels. Within each lobule, there are numerous small milk-producing glands called alveoli.

The mammary ducts are the main ducts that carry milk from the alveoli to the nipple. These ducts start from each lobe and converge towards the nipple, where they open into the lactiferous sinuses. The mammary ducts are lined with epithelial cells that secrete milk and are surrounded by myoepithelial cells that contract to help propel the milk towards the nipple.

The lactiferous ducts are larger ducts that receive milk from the mammary ducts and transport it to the nipple. These ducts are wider and more dilated compared to the mammary ducts. They are responsible for delivering the milk to the baby during breastfeeding.

The mammary tubules are the smaller branches of the mammary ducts that extend into the lobules and alveoli. These tubules are responsible for collecting and transporting milk from the alveoli to the larger mammary ducts.

The ampulla is a dilated portion of the lactiferous ducts located near the base of the nipple. It acts as a storage reservoir for milk and helps maintain milk flow during breastfeeding. The ampulla contracts and releases milk in response to the baby's sucking.

In summary, while all the options mentioned (mammary duct, lactiferous duct, mammary tubules, and ampulla) are involved in the transport and delivery of milk, the correct answer is option 'a) Mammary duct' as it is the main duct that carries milk from the alveoli to the nipple.