Four Resistors Having Resistances of 20 Ω,40 Ω,60 Ω,And 80

Multiple Choice

Four resistors having resistances of 20 Ω,40 Ω,60 Ω,and 80 Ω are connected in series across an ideal dc voltage source.If the current through this circuit is 0.50 A,what is the voltage of the voltage source?

A) 20 V
B) 40 V
C) 60 V
D) 80 V
E) 100 V