【单选题】In spite of rising concern in the Northeast and Canada, Administration spokesmen have repeatedly insisted that nothing could really be done about acid rain and the industry-produced sulfur emissions u...
A.
the Administration has ignored the public anxiety about acid rain.
B.
the industrial sulfur emissions need further scientific verification.
C.
the spokesmen have denied the presence of proofs of acid rain.
D.
scientific evidence has made the cause of acid rain undebatable.