Insulin is a protein hormone that regulates blood glucose levels and is a polymer of

The answer to this question would be: amino acids

Protein is polymer of amino acids, that mean that a protein is made from multiple amino acids. Insulin is a protein hormone that will cause glucose to move inside cells. The lack of insulin can cause a condition where the blood glucose is too high called diabetes mellitus

Its either a) or b),wind and water erosion gradually widen the canyon