Which of the following glands in the human body acts both as an endocrine gland and as an exocrine gland?

1. A

   Adrenal gland

   The adrenal gland is a pure endocrine gland. Cortex secretes corticosteroids and medulla secretes adrenaline and noradrenaline into blood. It has no duct that pours a digestive or other external secretion, so it is not both endocrine and exocrine.

2. B

   Lacrimal gland

   The lacrimal gland is exocrine: it pours tears through ducts onto the conjunctiva. It does not release hormones into blood as a dual gland, so it is not the key.

3. C

   Pancreas

   The pancreas is both endocrine and exocrine. Islets of Langerhans pour insulin, glucagon and related hormones into blood; acinar tissue pours pancreatic juice through the pancreatic duct into the duodenum. That dual character is why (c) is the official key.

4. D

   Thyroid

   The thyroid is a ductless endocrine gland secreting thyroxine, triiodothyronine and calcitonin into blood. It is not exocrine, so it is not the key.

Summary. Official key is (c). Only the pancreas among the given glands is mixed: endocrine islets and exocrine digestive juice. Adrenal and thyroid are endocrine only; the lacrimal gland is exocrine only.