Which of the following statements is/are correct regarding Nitrolim? I. It is made by heating calcium carbide with nitrogen. II. It decomposes in soil to give ammonia. III. It is an NPK fertilizer. IV. It is a biofertilizer. Select the answer using the code given below.

Nitrolim is calcium cyanamide (CaCN₂) mixed with carbon, prepared by heating calcium carbide (CaC₂) with nitrogen gas at about 1000 °C: CaC₂ + N₂ → CaCN₂ + C. In moist soil, CaCN₂ hydrolyses progressively to give ammonia (and ultimately urea), which supplies nitrogen to crops. Hence statements I and II are correct. Nitrolim is a nitrogenous fertilizer — not NPK (which requires N, P and K) and not a biofertilizer (it is a chemical/synthetic fertilizer, not derived from microorganisms). Therefore only I and II are correct.