Which of These Statements Correctly Describes Sweating

Which of these statements correctly describes sweating?

A) It causes vasodilation of the skin vessels.
B) It is the body's only mechanism for losing heat.
C) It increases the insulative capacity of the skin so that less heat can be gained from the environment.
D) It is the only heat-loss mechanism available to the body when the environmental temperature is so high that a normal temperature gradient between the skin and the environment cannot be established.