People who switch to a low-calorie diet generally do not lose any weight. This is surprising since it is understood that decreasing the calories in one' s diet, while maintaining the same level of activity, causes one to lose weight. Which one of the following, if true, most helps to resolve the apparent discrepancy? ['Food that are low in calories tend to cost more money.', 'People who switch to low-calorie diets also tend to decrease their level of activity.', 'People who eat a low-calorie diet generally weigh less than people eating a higher calorie diet.', 'Foods that are low in calories generally taste worse than high-calorie foods.']