The correct answer is option D. "Pituitary gland".
Explanation:
The pituitary gland is a small structure located in the brain that is often known as the body's "master gland" for its role of controlling other glands that secrete hormones. The growth hormone is secreted by the anterior lobe of the pituitary gland. Therefore, if a child needs to receive injections of a growth hormone it is very likely that the child's body suffers from a problem with the pituitary gland and needs to receive an external source of growth hormone because the gland is not able to secrete it.
