The relation R is defined on the set of natural numbers as $\left\{\left(\mathrm{a}, \mathrm{b}\right): \mathrm{a}=2\mathrm{b}\right\}$. The ${\mathrm{R}}^{-1}$ is given by

• A

  $\left\{\left(2, 1\right), \left(4, 2\right), \left(6, 3\right).....\right\}$

• B

  $\left\{\left(1, 2\right), \left(2, 4\right), \left(3, 4\right)....\right\}$

• C

  ${\mathrm{R}}^{-1}$ is not defined

• D

  None of these