A parallel combination of two capacitors of capacities '2 C' and 'C' is connected across 5 V battery. When they are fully charged, the charges and energies stored in them be 'Q1', 'Q2' and 'E1', 'E2' respectively. Then \(\frac{E_1-E_2}{Q_1-Q_2}\) in J/C is (capacity is in Farad, charge in Coulomb and energy in J)
1
\(\frac{5}{4}\)
2
\(\frac{4}{5}\)
3
\(\frac{5}{2}\)
4
\(\frac{2}{5}\)