Answer: C . Paris Agreement
Step-by-step explanation:
You included no background passage or additional details to the question for me to know what contribution you speak of but the above is most probably the answer.
The U.S. never ratified the Kyoto Protocol so I don't think they had contribution requirements. The London Accords produces research for financial investors so has little to do with the U.S. as a whole.
The Geneva Convention is simply an agreement on conduct during wars so this does not require contributions. This leaves the Paris Agreement ... on Climate Change which has set targets on the emissions to be cut by developed countries so it is most likely the answer.