Which of the following groups consists of macronutrients essential for plant growth?

Explanation

Macronutrients required by plants include Calcium (Ca), Magnesium (Mg), and Sulfur (S), which are essential for various physiological functions. While Nitrogen (N), Phosphorus (P), and Potassium (K) are also macronutrients, the question specifically highlights the group Ca, Mg, and S as macronutrients. Carbon (C), Hydrogen (H), and Oxygen (O) are basic elements but are not classified as macronutrients in this context.