A Total Resistance of 3 $\Omega$ Is to Be Produced by Combining an Unknown Resistor R

Multiple Choice

A total resistance of 3.0 $\Omega$ is to be produced by combining an unknown resistor R with a 12 $\Omega$ resistor.What is the value of R and how is it to be connected to the 12 $\Omega$ resistor?

A) 2.4 $\Omega$ , parallel
B) 2.4 $\Omega$ , series
C) 4.0 $\Omega$ , parallel
D) 4.0 $\Omega$ , series
E) 9.0 $\Omega$ , series