The mismatched pair is a) adrenaline : pituitary gland because adrenaline is actually secreted by the adrenal glands, not the pituitary gland.
Explanation:
Adrenaline:
This hormone is produced by the adrenal glands and is associated with the “fight or flight” response.
Pituitary gland:
While the pituitary gland is considered the “master gland” due to its control over many other hormones, it does not produce adrenaline.
Why other options are correct:
Testosterone : Testes: Testosterone is a male sex hormone produced by the testes.
Estrogen : Ovary: Estrogen is a female sex hormone produced by the ovaries.
Thyroxin : Thyroid gland: Thyroxin is a hormone produced by the thyroid gland.