Light with an average flux of 20 $\mathrm{W}/{\mathrm{cm}}^2$ falls on a non-reflecting surface at normal incidence having surface area 20 ${\mathrm{cm}}^2$. The energy received by the surface during time span of 1 minute is:

• A

  $12{\text{ x 10}}^3\mathrm{J}$

• B

  $24{\text{ x 10}}^3\mathrm{J}$

• C

  $48{\text{ x 10}}^3\mathrm{J}$

• D

  $10{\text{ x 10}}^3\mathrm{J}$