Which hormone causes heart rate, breathing rate, and alertness to increase?

Catecholamines

Explanation:

Catecholamines are hormones made by your adrenal glands, which are located on top of your kidneys. Examples include dopamine; norepinephrine; and epinephrine (this used to be called adrenalin or adrenaline). Your adrenal glands send catecholamines into your blood when you're physically or emotionally stressed.

a, b, c - sides of a triangle

a + b > c

a + c > b

b + c > a

we have a = 5m and b = 11m. substitute:

5 + 11 > c

16 > c → c < 16

5 + c > 11         subtract 5 from both sides

c > 6

11 + c > 5         subtract 11 from both sides

c > -6

c < 16 and c > 6 and c > -6

thereofre your answer is 6m < c < 16m

d, i believe because of it's activity level