Question

what in the skin contracts when environmental temperatures decrease? a arrector pili b sweat glands c sebaceous glands d hair

Explanation:

When environmental temperatures decrease, the arrector pili muscles in the skin contract. This causes the hair to stand up, creating "goose - bumps." Sweat glands secrete sweat mainly in response to heat to cool the body. Sebaceous glands produce sebum for skin and hair lubrication and are not directly related to temperature - induced contraction. Hair itself does not contract in response to temperature changes.

Answer:

A. Arrector pili