The correct answer is A. Glucose.
Glucose is the main source of energy for the body. It is a simple sugar that is found in many foods, including fruits, vegetables, and grains. When glucose is broken down in the body, it releases energy that is used by cells to function.
Triglycerides are a type of fat that is found in the body. They are made up of three fatty acids and one glycerol molecule. Triglycerides are stored in fat cells and are used for energy when glucose is not available.
Proteins are made up of amino acids. They are essential for the growth and repair of tissues in the body. Proteins are also used for energy, but they are not the main source of energy.
Cholesterol is a waxy substance that is found in the body. It is used to make hormones, vitamin D, and bile acids. Cholesterol is also found in foods, such as meat, eggs, and dairy products.
In conclusion, glucose is the main source of energy for the body. It is a simple sugar that is found in many foods, including fruits, vegetables, and grains. When glucose is broken down in the body, it releases energy that is used by cells to function.