Why Did Environmentalists Oppose the North American Free Trade Agreement

Why did environmentalists oppose the North American Free Trade Agreement (NAFTA) ?

A) They worried that Mexican diesel trucks would pollute the nation's clean air.
B) They saw NAFTA pushing the further deforestation of Canada's lumber-rich mountains.
C) They expected increased transoceanic traffic to add to the nation's carbon footprint.
D) They worried that U.S. corporations would evade U.S. environmental regulations with a move to Mexico.