The correct option is D ZnSO4.6H2O & ZnSO4.H2O
ZnSO4.7H2OAbove 39∘C−−−−−−−→Below 70∘CZnSO4.6H2OAbove 70∘C−−−−−−−→ZnSO4.H2OAbove 280∘C−−−−−−−→O2+SO2+ZnO800∘C←−−−ZnSO4(Anhydrous)
This reaction is self-explanatory. As ZnSO4.7H2O is heated above 39 degree Celsius and below 70 degree Celsius, it loses one water molecule and further when ZnSO4.6H2O is heated above 70 degree Celsius, it loses 5 water molecules. Therefore, A is ZnSO4.6H2O and B is ZnSO4.H2O.