题目内容：
根据以下材料，回答题。
According to the first two paragraphs，the author thinks that
A．strong measures have been taken by the government to prevent global warming.
B．to reduce carbon emissions is all impossible mission.
C．despite the difficulty，scientists have some options to prevent global warming.
D．actions suggested by scientists will never be realized.
参考答案：
答案解析：