which does not have coordinate bond
A)SO2
B)HNO2
C)H2SO3
D)HNO3

HOW TO CHECK

If some element has excess of electrons on it or less electron on it then they get involved in co-ordinate bonds.
Draw lewis dot structures and check if there is positive charge on N in any of the structure ...and if there is no positive charge on N then its not making a dative bond.If S has lone pair on it  then it can also get involved in dative bonding with Oxygen which is very electronegative as compare to S.
Try to figure out answer now.
Check out if SO3 and H2SO4 will have dative bonds? If No why?

Did not get it. Can u explain in class tomorrow.

ans B and D ?

A B AND C