Answer:
[tex]\boxed {\boxed {\sf A.\ Protein}}[/tex]
Explanation:
Macromolecules play many important roles in the body. Let's list the functions of proteins, carbohydrates, and lipids.
Proteins:
- These molecules help with growth, building and repairing cells, transporting substances, and acting as enzymes or hormones.
Carbohydrates:
- These molecules are used for energy. They can provide quick energy, because they are easy to break down.
Lipids:
- These help store energy for later use, plus they are sometimes insulators and hormones.
Based on the information, the molecule responsible for repair and growth must be protein.
