The Heat Energy in a Pound of Body Fat Is

The heat energy in a pound of body fat is 3500 Calories. If a woman's diet has an average caloric intake of 2500 Cal/day, by what percentage must this be reduced if she wishes to lose 10 pounds in 30 days? [Assume that her level of physical activity remains the same during the 30 days as it was before dieting began.]

A) 7.1%
B) 14.2%
C) 46.7%
D) 53.3%