As shown in the figure below, a cube is formed with ten identical resistance $\mathrm{R}$ (thick lines) and two shorteing wires (dotted lines) along the arms AC and BD.
Resistance between point $\mathrm{A}$ and $\mathrm{B}$ is-

• Correct answer
  A

  $\mathrm{R} / 2$
• B

  $5 \mathrm{R} / 6$
• C

  $3 \mathrm{R} / 4$
• D

  $\mathrm{R}$

Hence, the correct answer is option: 'A'.