The correct answer is: B. Proteins
Nitrogen is an essential constituent of proteins. It is found in the amino acids that make up proteins. Proteins are essential for the growth and repair of tissues, the production of enzymes and hormones, and the transport of oxygen and nutrients in the blood.
Fats are also essential for the body, but they do not contain nitrogen. Fats are a source of energy and help to protect the body’s organs. They also help to absorb vitamins A, D, E, and K.
Vitamins are also essential for the body, but they do not contain nitrogen. Vitamins are needed for the proper functioning of the body’s cells and tissues. They also help to protect the body from disease.
Carbohydrates are the body’s main source of energy. They are made up of carbon, hydrogen, and oxygen. Carbohydrates do not contain nitrogen.
In conclusion, nitrogen is an essential constituent of proteins. It is found in the amino acids that make up proteins. Proteins are essential for the growth and repair of tissues, the production of enzymes and hormones, and the transport of oxygen and nutrients in the blood.