Which Individual's Activity Had the Highest Calorie Cost

Which individual's activity had the highest calorie cost?

A) Sara, who weighs 145 lb and did step aerobics (0.062 cal/lb/min) for 35 minutes
B) Ben, who weighs 180 lb and walked on the treadmill (0.048 cal/lb/min) for 25 minutes
C) Mary, who weighs 120 lb and rode her bike (0.076 cal/lb/min) for 20 minutes
D) Andrew, who weighs 163 lb and swam (0.058 cal/lb/min) for 30 minutes