In the Circuit Shown in the Figure, an Ideal Ohmmeter

Multiple Choice

In the circuit shown in the figure, an ideal ohmmeter is connected across ab with the switch S open. All the connecting leads have negligible resistance. The reading of the ohmmeter will be closest to

A) 7.5 Ω.
B) 10 Ω.
C) 30 Ω.
D) 40 Ω.
E) 60 Ω.