Which of the following species exists?

Which of the following is the incorrect order of $X-P-X$ bond angle?

Among the following,the correct statement$(s)$ is(are):
$A$. $Al(CH_3)_3$ has the three-centre two-electron $(3c-2e)$ bonds in its dimeric structure.
$B$. $BH_3$ has the three-centre two-electron $(3c-2e)$ bonds in its dimeric structure $(B_2H_6)$.
$C$. $AlCl_3$ has the three-centre two-electron bonds in its dimeric structure.
$D$. The Lewis acidity of $BCl_3$ is greater than that of $AlCl_3$.

In the $Al_2Cl_6$ dimer,which of the following statements is true regarding the $Al-Cl$ bonds?

Which of the following has a different number of $p_{\pi}-d_{\pi}$ bonds compared to the other molecules?

How many $S-S$ bonds,$S-O-S$ bonds,$\sigma$ bonds,and $\pi$ bonds are present in the trimer of $SO_3$?