​All of the following are explanations that researchers have suggested for why obesity has increased in the past two decades EXCEPT:

A) ​increased consumption of fast foods.
B) ​increased consumption of sweetened soda.
C) ​increased consumption of genetically modified foods.
D) ​decreased engagement in physical activity.

Genetically Modified Foods

Foods produced from organisms that have had changes introduced into their DNA through genetic engineering techniques to enhance certain traits like increased resistance to herbicides or improved nutritional content.

Fast Foods

Quick-service food items that are typically high in calories, fat, and sodium, and often consumed for convenience.

Physical Activity

Any bodily movement produced by skeletal muscles that requires energy expenditure, including exercise and daily activities.