$A$ wire of resistance $R$ is cut into $8$ equal pieces. From these pieces,two equivalent resistances are made by connecting four of these pieces in parallel in each set. Then,these two sets are connected in series. The net effective resistance of the combination is

• A
  $\frac{R}{64}$
• B
  $\frac{R}{32}$
• C
  $\frac{R}{16}$
• D
  $\frac{R}{8}$