The N in all fertilisers comes from

Answer: Option C

The N in all fertilizers comes from Air.
For nitrogen-based fertilizers, the largest product group, the process starts by mixing nitrogen from the air with hydrogen from natural gas at high temperatures and pressure to create ammonia.
The Haber process produces ammonia (NH₃) from methane (CH₄) (natural gas) gas and molecular nitrogen (N₂) from the air.