Which one of the following is not a micronutrient?
a)	Molybdenum	b)	Magnesium	c)	Zinc	d)	Boron

(b)

 The essential elements, which are required by plants in comparatively large amounts, are called as microelements, e.g., C, H, O, N, P, K, Ca, S, Mg, Fe.

The essential elements, which are required in very small amount by the plants are called microelements, e.g., Zn, Mn, B, Cu, Mo and Cl.