Select the correct answer. what is the difference between heat exhaustion and heat stroke? a. heat exhaustion is a decrease in blood volume, while heat stroke is an increase in blood volume. b. heat exhaustion is an increase in blood volume, while heat stroke is a decrease in blood volume. c. heat exhaustion involves extreme sweating, while heat stroke involves a lack of sweating. d. heat exhaustion involves a lack of sweating, while heat stroke involves extreme sweating.