Which of the following nutrients is categorized under macronutrients in the mineral nutrition classification?

 

A. Zn
B. Mn
C. Fe
D. Cl
E. K

Potassium is classified as a macronutrient because plants require it in large amounts for normal growth and development. It plays a crucial role in enzyme activation, osmotic balance, and regulation of stomatal opening, thereby improving photosynthesis and stress tolerance. Other options listed are micronutrients, required only in trace quantities