(i) Spraying urea with neem oil slows the release of nitrogen, by about 10 to 15 per cent, concomitantly reducing consumption of the fertiliser. Many research studies in India have conclusively established that neem oil acts as an effective nitrification inhibitor if coated onto urea (ii) Spraying urea with neem oil slows the release of nitrogen, by about 10 to 15 per cent, concomitantly reducing consumption of the fertiliser. Hence mathrmB is the closet answer.