What Is the Equivalent Resistance Between Points a and B $\Omega$

Multiple Choice

What is the equivalent resistance between points a and b when R = 12 $\Omega$ ?

A) 20 $\Omega$
B) 16 $\Omega$
C) 24 $\Omega$
D) 28 $\Omega$
E) 6.0 $\Omega$