Explanation:
It is given that,
Voltage of the battery, V = 12 V
Current, I = 100 ampere-hours
Energy stored is given by the product of power and time taken. So,

P is the power, 

P = 1200 watts
This power can be used for 1 hour or 3600 seconds
Energy, 
E = 4320000 J
So, the energy stored in this battery is 4320000 J. Hence, this is the required solution.
soil i think is this from apex?
You can increase the capacitance of a capacitor by decreasing the plate spacing (A) or by increasing the area of the plates (D).
'A' and 'D' both do the job, so the correct choice is<em> (E)</em> .