Which of the following species contains equal number of $\mathrm{\sigma }$ - and $\mathrm{\pi }$ - bonds?

Given below are the structures of the molecules given in the options.

  $=4\sigma ,1\pi$ bond

$=4\sigma ,4\pi$ bond

$=3\sigma ,4\pi$

$=6\sigma ,4\pi$ bond

Hence, XeO₄ contains equal number of sigma and pi bonds.

(Double bond contains one sigma and one pi bond and triple bond contains one sigma and 2 pi bonds).