In an aluminum (Al) bar of square cross section, a square hole is drilled and is filled with iron (Fe) as shown in the figure. The electrical resistivities of Al and Fe are $$2.7 \times 10^{-8} Ω m$$ and $$1.0 \times 10^{-7} Ω m,$$ respectively. The electrical resistance between the two faces P and Q of the composite bar is

A

$$\frac {2475}{64} \muΩ$$

B

$$\frac {1875}{64} \muΩ$$

C

$$\frac {1875}{49} \muΩ$$

D

$$\frac {2475}{132} \muΩ$$