Which of the following are inorganic substances that are essential for life?

Minerals are indeed inorganic substances that play crucial roles in various physiological processes essential for life. They are defined as elements that are not made from living organisms and are required in small amounts for optimal health. Minerals such as calcium, potassium, iron, and magnesium are vital for numerous bodily functions including bone formation, muscle contraction, nerve transmission, and maintaining overall fluid balance.

Vitamins, while also essential for health, are organic compounds, meaning they contain carbon and are derived from living organisms. Proteins and carbohydrates are macromolecules that consist of carbon-based structures and are also classified as organic substances. Hence, among the options provided, minerals are the only inorganic substances that are directly required for many physiological activities in the body, confirming their essential role in sustaining life.