The correct option is A Boron
The movement of sucrose and other substances like amino acids around a plant is called translocation. Plants require seven micronutrients which are boron, zinc, copper, manganese, molybdenum, iron and chlorine. Boron is an essential micronutrient for plants. It is required for transportation of sugars.
Molybdenum, in molybdate form, is essential for plants as a number of enzymes use it to catalyze most important reactions in the nitrogen acclimatization, the synthesis of the phytohormone, degradation of the purine and the detoxification of the sulfite.
Manganese (Mn) is an important micronutrient for plant growth and development . It is an essential cofactor for the oxygen-evolving complex (OEC) of the photosynthetic machinery, catalyzing the water-splitting reaction in photosystem II (PSII).
Iron is required in larger amounts as compared to other micronutrients. It is an important constituent of protein and helps with the activation of enzymes.
So, the correct answer is "option A"