Which one is a fertilizer?

Sodium Nitrate (${\text{NaNO}}_3$), commonly referred to as Chile saltpeter, serves as a direct source of nitrogenous nutrition for agricultural crops and is utilized as a chemical mineral fertilizer. Elemental gases like ${\text{N}}_2$, ${\text{O}}_2$, or allotropes like ${\text{P}}_4$ cannot be directly absorbed as soil manure or salt-based fertilizer blocks.