​Obesity can result from

A) ​overeating.
B) ​slow metabolism.
C) ​too little physical activity.
D) ​any or all of these.

Obesity can result from any of these factors, and often it is a combination of them that leads to weight gain and difficulty losing weight. Overeating can cause an excess of calories to be consumed, which can lead to weight gain if the body does not burn these calories off through physical activity or a high metabolism. A slow metabolism can make it more difficult for the body to burn calories, and too little physical activity can make it harder for the body to use up the energy it takes in from food. Therefore, any or all of these factors can contribute to obesity.