How much farmyard manure is required for obtaining 60 kg nitrogen for a crop?

Answer: Option B

FYM (farmyard manure) is an important organic resource for agricultural production in livestock-based farming systems in the semi-arid tropics of India.
The chemical composition of FYM is nitrogen is 0.5% nitrogen, 0.2% phosphate. 0.5% potassium and 76% of water.
For 60 kg of nitrogen for a crop, 120 tonnes of farmyard manure is required as 1 ton of FYM contains 0.5 kg of Nitrogen.