Which of the following is INCORRECT????

Some operations which can be performed on a capacitor are defined below :
A : Connect the capacitor to a battery of emf E
B : Disconnect the battery
C : Reconnect the battery with polarity reversed
D : Insert a dielectric slab into the capacitor.
Now choose the incorrect option(s).
a- In action ABC (A then B then C) the stored electric energy remains unchanged and no thermal energy is developed.
b- The charge appearing on capacitor is greater after ADB than after ABD
c- The electric energy stored in the capacitor isgreater after DAB than after ADB
d- The electric field in the capacitor after AD is same as that after the action DA.

Please explain...