Fact 1: Insulin helps cells take up glucose from the blood.

Fact 2: Blood Glucose Blood Glucose Glucose is the principal source of energy for mammalian cells.

Given the two facts above, answer the question "Cells obtain energy from the blood with the help of" with the following options: 
- sweating
 - batteries
 - pancreas
 - electron
 - insulin
 - alveoli
 - oxygen
 - sunlight


 

     insulin    