Following statements are regarding to the heat production by the activation of sympathetic nervous system.A. Activation is stimulation of β receptors in brown fat, which increases metabolic rate and heat production.B. Activation is stimulation of α2 receptors in brown fat, which increases metabolic rate and heat production.C. Stimulation of α1 receptors in vascular smooth muscle of skin blood vessels, producing vasoconstriction. Vasoconstriction reduces blood flow to the surface of the skin.D. Stimulation of α1 receptors in vascular smooth muscle of skin blood vessels, producing vasodilation. Vasodilation reduces blood flow to the surface of the skin.Which of the following combination is correct? -triyambak.org