When you start to exercise, the body responds in various ways due to internal stimuli. one response is an increase in heart rate. identify a stimulus that would cause an increase in heart rate.
a. a decrease in body temperature
b. an increase in oxygen levels in the blood
c. a decrease in the rate of cellular respiration
d. an increase in carbon dioxide levels in the blood?

The correct answer is D) An increase in carbon dioxide level in the blood.

During exercise, contraction of muscles take place very quickly as they work harder during exercise. As more oxygen is required to burn calories efficiently, the demand for oxygen supply increases.  

When we start exercising, body temperature increases as the rate of cellular respiration also increases.

An increase in carbon dioxide in the blood causes increase in heart rate as there is more demand of oxygen for efficient contraction of the muscles.

"1. it should be, it has been for about 20 years, and it's really not much different in the end than breeding animals to have particular traits. there are always concerns about genetically engineered animals/plants affecting the environment in unexpected negative ways, but i can't think of an example where the fears didn't turn out to be baseless.  

first, as you point out, it would be a great advance in pharmacology, to be able to tailor drugs and their doses to me. the pros involve better medical treatment. the cons involve privacy issues like insurance companies denying coverage to people with genetic risk factors. looking at dna markers wouldn't affect the frequency of genetic diseases, but it would allow detection of them earlier. and ok, actually i suppose that if people used this information to avoid having children with genetic diseases, some might decrease in frequency."

the answer is c most of the fortnite players usually buy v bucks to get the battle pass and other cosmetics but some players who are referred to as "no skins" don't   buy skins and are usually noobs.