ADH _______________.
a. Increases water absorption
b. Decreases water absorption
c. Synthesis salt
d. Controls sugar level of blood

Hint: ADH or Antidiuretic hormone is also known as vasopressin or pitressin. It is a hormone secreted by the posterior pituitary gland and it helps in the maintenance of blood osmotic potential.

Complete answer:
- The posterior lobe of the pituitary releases two peptide hormones that are the products of the hypothalamus and they reach the pituitary through the axon terminals of the secretory neurons as secretory granules.
- The first hormone is ADH that helps in the osmoregulation. It controls the volume of urine by increasing water reabsorption in the nephric tubules. This makes the urine hypertonic.
- This hormone also helps in bringing back the normalcy in the autonomous nervous system during the period of stress, pain, anger and excitement.
- Alcohol inhibits ADH secretion that increases the urine volume.
- The other hormone is oxytocin that facilitates the childbirth by loosening pubic symphysis and also helps in releasing milk from the mammary glands by relaxing the muscles of the nipple.
- The sugar level of blood is controlled by two hormones- glucagon and insulin that are released by the Islets of Langerhans of the pancreas. Insulin is hypoglycemic and it converts glucose into glycogen while glucagon is hyperglycemic and promotes gluconeogenesis.
- Mineralocorticoid or aldosterone controls the plasma sodium and potassium levels or salt levels and maintains low blood pressure.

Hence, the correct answer is option (A).

Note: The deficiency of the level of ADH causes diabetes insipidus or drinking disease which is characterized by polyuria i.e. loss of abnormal amount of water in urine and to compensate it the patient keeps taking an equally high amount of water i.e. polydipsia or excessive thirst.