The first one It sends signals that control heart rate and respiration. I hope this helps :)
Answer:
option D
Explanation:
this is because it occurs in many different dimensions, including biological, cognitive and socioemotional. this is also the answer on apex.
Answer:

So a=3.844 and b=5
Explanation:
Scientific notation requests to write a number using powers of ten as a factor accompanying a real number (a) between 1 and smaller than 10 that contains the digits to exactly represent the original number. So in this case, the number 384,400 can be written as:

with a=3.844, and "5" as the exponent of ten (so b=5)
A scalar quantity is a measurement of a quantity, like temperature, or mass.