Answer:
[tex]\huge\boxed{\sf Option \ 4}[/tex]
Explanation:
Nervous System:
- Nervous system send electrical signals in the form of nerve impulses to control the body functions and regulate them as well.
- Brain and Spinal cord are the main parts of nervous system also called central nervous system.
- Neurons are the smallest unit of the nervous system.
Endocrine System:
- Endocrine system involves the production of secretions and sending signals in the form of chemicals.
- Hormones are the main secretions of the endocrine system. They are the main chemical messengers of endocrine gland.
[tex]\rule[225]{225}{2}[/tex]
