The Intensity of Radiation Reaching the Earth from the Sun

Multiple Choice

The intensity of radiation reaching the Earth from the Sun is 1350 W/m². The Earth's radius is 6.4 × 106 m. How big a force does this radiation exert on the Earth? (Assume it is all absorbed.)

A) 5.8 × 108 N
B) 1.2 × 109 N
C) 2.3 × 109 N
D) 4.6 × 109 N
E) 1.7 × 1017 N