Magnetic field at the center of a circular coil is B. If area of the coil is A  then magnetic moment of the loop is 

• A

  $\frac{{\mathrm{BA}}^2}{{\mathrm{\mu }}_0\mathrm{\pi }}$

• B

  $\frac{\mathrm{BA}\sqrt{\mathrm{A}}}{{\mathrm{\mu }}_0}$

• C

  $\frac{\mathrm{BA}\sqrt{\mathrm{A}}}{{\mathrm{\mu }}_0\mathrm{\pi }}$

• D

  $\frac{2\mathrm{BA}}{{\mathrm{\mu }}_0}\sqrt{\frac{\mathrm{A}}{\mathrm{\pi }}}$