Part a: which statement identifies the central idea of the text?

a
whether the scary experience is real or not, people often feel a sense of relief after they experience what is easily mistaken for elation.
b
while the brain function of some people decreases following a scare, other people experience increased brain function related to stress.
c
experiencing fun-scary things together has proven to strengthen bonds between people and make relationships last longer.
d
many people who willingly engage in scary experiences in safe settings experience positive reactions in their brains.