The correct option is A PTH
Hormone X is - PTH (Parathormone/Parathyroid Hormone/Collip’s Hormone)
Functions of PTH are-
(i) Regulate calcium-phosphate level in blood.
(ii) Increase the rate of calcium, absorption from intestine.
(iii) Helps in the bone dissolution of newly formed asymmetric bone.
(iv) Affects the growth of bones, membrane permeability, nerve functioning and muscular activity of blood.