A car starts from rest and moves with constant acceleration. The ratio of the distance covered in the nth second to that covered in n seconds is

• A

  $\frac{2}{{\mathrm{n}}^2}-\frac{1}{\mathrm{n}}$

• B

  $\frac{2}{{\mathrm{n}}^2}+\frac{1}{\mathrm{n}}$

• C

  $\frac{2}{\mathrm{n}}-\frac{1}{{\mathrm{n}}^2}$

• D

  $\frac{2}{\mathrm{n}}+\frac{1}{{\mathrm{n}}^2}$