In which of the following compounds, nitrogen exhibits highest oxidation state?

Calculating oxidation states of N:${\text{NH}}_2\text{OH}$ (Hydroxylamine): $x+2(1)+(-2)+1=0⟹x=-1$.${\text{N}}_2{\text{H}}_4$ (Hydrazine): $2x+4(1)=0⟹x=-2$.${\text{NH}}_3$ (Ammonia): $x+3(1)=0⟹x=-3$.${\text{N}}_3\text{H}$ (Hydrazoic acid): $3x+1=0⟹x=-1/3$.Comparing $-1,-2,-3$, and $-1/3$, the value $-1/3$ is the highest (mathematically closest to zero/least negative).