Multiple choice Which of the following is a micronutrient? Mg Zn P K Reveal answer Fill a bubble to check yourself B Correct answer Explanation Micronutrients are essential elements required by plants in very small quantities. Zinc (Zn) is a micronutrient, while Magnesium (Mg), Phosphorus (P), and Potassium (K) are macronutrients required in larger amounts.