单选题 Which of the following, according to the author, should play the leading role in the solution of environmental problems?

A、 Legislation and government intervention.
B、 The industry' s understanding and support.
C、 The efforts of environmental health professional.
D、 The cooperation of ecologists, environmental activists and conservationists.

【正确答案】 D

【答案解析】[试题分析] 本题为作者观点题。
[详细解答] 从文中If ever there will be time for environmental health professionals to come to the frontlines and provide leadership to solve environmental problems，that time is now．(如果要让环保专家站出来充当领导的话，现在是时候了。)以及综合全文来看，作者的观点是明确的，即环保专家们应担负起领导责任。