Which of the following is an example of negative feedback loop in humans?

Options

(a) Secretion of tears after falling of sand particles into the eye.
(b) Salication of mouth at the sight of delicious food
(c) Secretion of sweat glands and constriction of skin blood vessels when it is too hot.
(d) Constriction of skin blood vessels and contraction of skeletal muscles when it is too cold.

Correct Answer:

Constriction of skin blood vessels and contraction of skeletal muscles when it is too cold.

Explanation:

When the set point of hypothalamus is distributed by high temperature, it stimulates casodilation and sweating while in low temperature there is vasoconstriction and shivering.