34. The figures above show parts of two circuits, each containing a battery of emf ε and internal resistance r. The current in each battery is 1 A , but the direction of the current in one battery is opposite to that in the other. If the potential differences across the batteries' terminals are 10 V and 20 V as shown, what are the values of E and r ?
(A) E=5V,r=15Ω
(B) E=10V,r=100Ω
(C) E=15V,r=5Ω
(D) E=20V,r=10Ω
(E) The values cannot be computed unless the complete circuits are shown.