Which of the following is a macronutrient?

Explanation

Carbon is indeed a macronutrient. It is one of the fundamental building blocks of all organic molecules, including carbohydrates, proteins, lipids, and nucleic acids, which are essential components of living organisms. Carbon is obtained through the consumption of organic matter in food and is a primary source of energy for living organisms. Now we'll look at why other options are incorrect.The correct answer is (d) carbon.Explanation:(a) Boron: Boron is a mineral and is considered a micronutrient, not a macronutrient. While it is essential for plant growth, it is required in very small amounts.(b) Iron: Iron is also a mineral and is classified as a micronutrient. It is essential for human health, particularly for the production of red blood cells, but it is needed in relatively small quantities compared to macronutrients.(c) Copper: Like boron and iron, copper is a mineral and falls under the category of micronutrients. It is required in trace amounts for various physiological functions in humans and other organisms.(Environmental chemistry,Components of Environment )