Calcium, Sulphur, Boron, Copper, and Iron are
Macronutrients
Micronutrients
Immmobile elements
Mobile elements
Essential Elements on the Basis of Their Mobility -
Essential elements can also be divided on the basis of their mobility within a plant and their tendency to translocate within the plant during deficiencies:
Immobile elements such as Calcium, Sulphur, Boron, Copper, and Iron essentially get locked in place and that is where they stay. Hence, the correct answer is option c.