Unlike minerals such as iron and calcium, protein is a macronutrient in the human diet. why is protein a macronutrient?

a.
proteins are one of the few inorganic compounds that humans eat.

b.
the human diet requires a relatively large amount of protein.

c.
the human diet should be made up of mostly protein.

d.
proteins are the most calorie-dense molecules that humans eat.

The correct answer is option B, that is, the human diet requires a relatively large amount of protein.

The micronutrients are this that are required in small quantities and their function is not that broad. However, macronutrients refer to those that monitor all the metabolic cycles of the cell, so they are required in large numbers.  

The proteins are considered as macronutrients as they are required in huge quantities, they take part in some of the major activities of the body. For example, proteins are involved in immunity, functions as enzymes, sustain homeostasis of the body, and other things.