In an aluminium (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 x 10–8 Ω m and 1.0 x 10-7 Ω m, respectively. The electrical resistance between the two faces P and Q of the composite bar is
(A) 2475/64 μΩ
(B) 1875/64 μΩ
(C) 1875/49 μΩ
(D) 2475/132 μΩ
