Which sentence has a gerund functioning as object of a preposition

Which statement best supports the author's purpose in "children of the drug wars," which is to persuade readers that the united states should do more to immigrant children from honduras?

Critical thinking questions what factors led to the creation and implementation of operation reinhard? how did the residents of the ghettos respond to mass deportations and what occurred when the residents realized what happened to those deported? what did rudolf hoess’s testimony at the end of the war suggest about the final solution and planned deportation and resettlement? how did operation reinhard differ from earlier nazi actions and how was it similar? was resettlement seriously considered and why was it not used?

What is the central idea in this advice from branch rickey to jackie robinson?