$\mathrm{A}$ and $\mathrm{B}$ are two points on a uniform ring of resistance $\mathrm{R}$ the $\angle \mathrm{AOB}=\theta_{3}$ where $\mathrm{O}$ is the centre of the ring. The equivalent resistance between $\mathrm{A}$ and $\mathrm{B}$ is.
(A) $(\mathrm{R} \theta / 2 \pi)$
(B) $[\{\mathrm{R}(2 \pi-\theta)\} /\{4 \pi\}]$
(C) $\mathrm{R}[1-(\theta / 2 \pi)]$
(D) $\left\{\mathrm{R} /\left(4 \pi^{2}\right)\right\}(2 \pi-\theta) \theta$