I found the whole exercise on the internet. Here are the options:
"A your REE is increased.
B your food intake that supported a normal weight is the same.
C your body can lose the ability to increase energy expenditure.
D none of the above"
The correct answer is C.
By dieting, time after time, with no exercise, the body adapts itself to the new condition of lesser calories intake by interpreting it as a starving mode, entering into a slower metabolism in order to save up energy. This starving mode will lead to a decrease even in resting energy expenditure as well as in any other expenditure. Although the individual that does such diet may lose some weight at first, it will eventually slow down that process and, if it returns to the same calories intake, it will quickly return to the same weight or more - this is because the body's energy use is managed now from a saving up energy strategy.