Which of the following statement is wrong?

1. A
   Nitrogen cannot form $d\pi -p\pi$ bond.
2. B
   Single $\text{N}-\text{N}$ bond is weaker than the single $\text{P}-\text{P}$ bond.
3. C
   ${\text{N}}_2{\text{O}}_4$ has two resonance structures.
4. D
   The stability of hydrides increases from ${\text{NH}}_3$ to ${\text{BiH}}_3$ in group $15$ of the periodic table.