Which of the following statement is wrong ?

Single $N-N$ bond is weaker than the single $P-P$ bond

$\mathrm{N}_{2} \mathrm{O}_{4}$ has two resonance structures

The stability of hydrides increases from $\mathrm{NH}_{3}$ to $\mathrm{BiH}_{3}$ in group 15 of the periodic table

Nitrogen cannot form $\mathrm{d} \pi$-p $\pi$ bond