What is the primary function of $Oxytocin$?

$A$ patient complains of constant thirst,excessive passing of urine,and low blood pressure. When the doctor checked the patient's blood glucose and blood insulin levels,the levels were normal or slightly low. The doctor diagnosed the condition as diabetes insipidus. However,the doctor decided to measure one more hormone in the patient's blood. Which hormone does the doctor intend to measure?

Given below are two statements.
Statement $I$ - Highest secretion of growth hormone $(GH)$ is seen till puberty.
Statement $II$ - The $GH$ is secreted continuously throughout life for repair and replacement of cells.
In the light of above statements,select the correct option given below:

Select the correct statement from the following.

The pituitary gland is derived from which germ layer?

Which hormone controls other endocrine glands?