In which of the following bond angle cannot be explained by Valence Bond theory?

The bond angle in H2O cannot be explained by VBT and the concept of hybridization is required.But the bond angles of other hydrides of these family can be explained by VBT. According to Drago's rule, bonding in these hydrides occurs via pure p orbitals and not hybrid orbitals. This is the reason bond angle in them is close to 90∘.