A series circuit has two 5.0-ohm resistors and a power source of 9.0 volts. How will the current be affected and what will it be if another resistor (with a resistance of 7.5 ohms) is added to the circuit?
A.increase; 0.51 amps
B.increase; 0.72 amps
C.increase; 3.6 amps
D.decrease; 0.51 amps
E.decrease; 0.72 amps