Shawn was cleaning up storm debris and encountered a large spider. He shouted and moved away from the spider, and he felt his heart rate increase. After a few minutes, he began to calm down and his heart rate returned to normal. Which part of the nervous system is responsible for decreasing his heart rate and calming down?
A) Central nervous system
B) Parasympathetic nervous system
C) Somatic nervous system
D) Sympathetic nervous system