The correct answer is "The rebels promised to provide laborers to help the United States build the Panama Canal. "
The US was initially reluctant to make any efforts in constructing the canal after the French had failed in its attempt to do so. However, French engineer Philippe-Jean Bunau-Varilla managed to negotiate a deal with the US government in order for it to continue with the project. This deal included the support to the Panamanians independentist efforts.
Local diseases were a big issue during the construction of the canal, as workers and administrative personnel fell ill and died due to them. Panamanians offers locals as a labor force in exchange for US support in the rebellion and the deal was finalized.
After the war ended, the United States was granted a perpetual lease of the canal and its operations.