According to the research carried out by York University researchers, for obese people,A．t

According to the research carried out by York University researchers, for obese people,

A．they should lose weight before evaluating their health conditions.

B．not gaining any weight is easier to achieve than losing weight.

C．they are likely to benefit a lot from losing their weight.

D．having a healthy lifestyle. is more important than losing weight.

请帮忙给出正确答案和分析，谢谢！