What is the difference between heat exhaustion and heat stroke?

AHeat exhaustion is a decrease in blood volume, while heat stroke is an increase in blood volume.

BHeat exhaustion is an increase in blood volume, while heat stroke is a decrease in blood volume.

CHeat exhaustion involves extreme sweating, while heat

stroke involves a lack of sweating.

DHeat exhaustion involves a lack of sweating, while heat stroke involves extreme sweating.