please help fast!!!!
Which is the correct definition of insulin?



 
A.
A substance in the joints that causes painful swelling and stiffness.


 
B.
A disease that prevents the body from converting food into energy.


 
C.
A hormone produced in the pancreas that regulates the level of glucose in the blood.


 
D.
A chronic disease characterized by pain, inflammation, swelling, and stiffness of the joints.