The correct option is C Submaxillary salivary duct
Brunner's glands are found in the duodenum region of small intestine. Their secretions protect the walls of the intestine from the action of gastric juices.
Sublingual salivary glands are the smallest glands present beneath the tongue These open at the floor of buccal cavity through ducts of Rivinus.
Submaxillary salivary gland are also called submandibular glands. These are medium sized glands and the duct of these glands is called Wharton's duct that opens in the oral cavity near the lower central incisors.
Parotid salivary glands are the largest salivary glands of the body. The duct of these glands is called Stenson's duct.
So, the correct answer is 'Submaxillary salivary gland'.