【正确答案】 D

【答案解析】[解析] 第二段末尾Behren的几句话告诉我们，对由谁来负责旅游保健业务，目前还存在分歧。("The NHS consultant finds it difficult to define travelers’health，”says Ron Behrens．．．“Should it come within the NHS or should it be paid for? It's a grey are- a，and opinion is split．No one seems to have any responsibility for defining its role，”he says．)因此[A]、[B]、[C]都不确切，只有[D]是正确的。