Which scenario would most likely cause a mass extinction?

a. global temperatures drop several degrees after several massive volcanic eruptions
b. a disease kills off a single species of predator within an ecosystem
c. a massive earthquake strikes north america
d. a wildfire burns a national park

(i think it would be b)

A. global temperatures drop several degrees after several massive volcanic eruptions

what statement best describes the difference between the sympathetic and parasympathetic nervous systems?

the sympathetic nervous system prepares the body for intense physical activity and is often referred to as the fight-or-flight response. the parasympathetic nervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.

im not intirely sure but i think the anwser is d relative humidity