The endocrine system.
It releases hormones from the glands; and also controls thirst, and sleep. Which is quite interesting.
Hey there!
The correct answer to your question is true.
It is true that using the right tone can help you have good interpersonal relations with others. This is because when you have a nice tone, people will think that you are a very friendly person. If you were to have a rough/angry tone towards other people, they will not pick up the greatest vibes from you, meaning that they will think you are an unfriendly person.
Hope this helps you.
Have a great day!
I will! What do you need help with?
The part of the brain that is associated with pleasure and reward. Anterior cingulate cortex and striatum (triathlete.com)