Which of These Is TRUE of the Paris Climate Treaty

Which of these is TRUE of the Paris Climate Treaty?

A) It was an agreement with no enforcement mechanisms to limit carbon emissions and 174 countries signed it on Earth day April 22,2016,including the U.S
B) It was an agreement with rigorous enforcement mechanisms to limit carbon emissions and 174 countries signed it on Earth day April 22,2016,including the U.S.
C) It was an agreement with no enforcement mechanisms to limit carbon emissions and 174 countries signed it on Earth day April 22,2016,but the U.S.declined to sign
D) It was an agreement with rigorous enforcement mechanisms to limit carbon emissions and 174 countries signed it on Earth day April 22,2016,including the U.S..