Which of these describes efforts made by $Cl$ at this site?

a$.$ They registered the project as part of the climate change mitigation strategy developed under the UN Framework Convention on Climate Change

b$.$ All of these answers are correct

c$.$ They sold millions of dollars' worth of carbon credits to the Walt Disney Company to offset the emissions from its cruise liners

d$.$ They asked farmers to sign agreements to refrain from cutting down trees and expanding their farms