The correct answer is (d). Insulin is a protein hormone which is produced in the pancreas. It is responsible for regulating blood sugar levels by helping cells absorb glucose from the bloodstream. Insulin is essential for life, and people with diabetes do not produce enough insulin or cannot use it effectively. This can lead to high blood sugar levels, which can damage organs and tissues over time.
(a) is incorrect because insulin is a protein hormone. Protein hormones are made up of amino acids, which are the building blocks of proteins. Insulin is produced by the beta cells in the pancreas.
(b) is incorrect because insulin is not a steroid hormone. Steroid hormones are made up of cholesterol. Insulin is not made up of cholesterol.
(c) is incorrect because insulin is not a cholesterol-driven hormone. Cholesterol is a type of lipid that is found in the blood. Insulin is not a lipid.