单选题 The debate as to which is the best way to lose weight has never come to an end.
【正确答案】 D
【答案解析】该句意为：有关减肥最佳方法的争论从未停止过。as to的意思是“关于”，常接疑问词引导的从句。considering：考虑到；including：包括；relating需要与to连用，等于related to；concerning：关于。