Which of these have inter-molecular hydrogen bond?
For H-bonding, H should be attached to a highly electronegative atom.
KH2PO4 is very similar to H3PO4. From VSEPR, you will see that H-bonding condition is satisfied.
From VSEPR, KH2PO4 looks like
H3BO3 looks like
Each H is attached to O and can form H-bonding.
Benzoic acid can form H-bonding by using H attached to O in the -COOH part.
In methanol
(CH3OH), the H atom attached to the electronegative O will form intermolecular H-bond with other methanol molecule.
Thus, A, B, C and D are right.