Correct option is D
✅ (d) 17: • A total of 17 essential elements are required by plants, classified into:
· Macronutrients (C, H, O, N, P, K, Ca, Mg, S)
· Micronutrients (Fe, Mn, Zn, Cu, B, Mo, Cl, Ni) • All must be available in optimum quantity for healthy growth.