The correct option is D p>r>q
Stability of the canonical structures are decided by following factors.
i) Neutral structures are most stable.
ii) Greater the number of covalent bonds, greater is the stability
iii) Structure with a negative charge on the more electronegative atom will be more stable.
iv) Charge separation: like charges should be at the maximum distance.
Hence, the stability order is:p>r>q