Resonance hybrid of nitrate ion is

• A

  $\begin{matrix}
     ^{-1/2}O\underline{\overline{\cdots }}N\underline{\overline{\cdots }}{{O}^{-1/2}}  \\
     |\vdots |  \\
     \,\,\,\,\,\,\,\,\,{{O}^{-1/2}}  \\
  \end{matrix}$

• B

  $\begin{matrix}    ^{-2/3}O\cdots N\cdots {{O}^{-2/3}}  \\
     \vdots   \\
     \,\,\,\,\,\,\,\,\,{{O}^{-2/3}}  \\
  \end{matrix}$

• C

  $\begin{matrix}
     ^{-2/3}O\cdots \overset{+}{\mathop{N}}\,\cdots {{O}^{-2/3}}  \\
     \vdots   \\
     \,\,\,\,\,\,\,\,\,{{O}^{-2/3}}  \\
  \end{matrix}$

• D

  $\begin{matrix}
     ^{-1/3}O\underline{\overline{\cdots }}N\underline{\overline{\cdots }}{{O}^{-1/3}}  \\
     |\vdots |  \\
     \,\,\,\,\,\,\,\,\,{{O}^{-1/3}}  \\
  \end{matrix}$