Which of the following is known as ‘the master gland of the body’?

The pituitary gland is a pea-sized endocrine gland located in the anterior portion of the brain. It is attached to the hypothalamus through a stalk. It controls many vital functions of the human body by producing important hormones. 

It is known as the master gland because it controls other glands by stimulating them to produce their hormones.

For example, it releases TSH (thyroid stimulating hormone) which in turn reaches the thyroid gland and stimulates it to produce the required amount of hormone thyroxine.