Read the lines from The Elements of San Joaquín.The sky went black in the ninth hour of rolling trays,And in the distance ropes of rain dropped to pull meFrom the thick harvest that was not mine.

The speaker describes working for hours in the harvest, then says the harvest “was not mine.” This suggests the workers do the hard labor while someone else owns or receives the crops. So the best choice is “The workers labor very hard for other people.”

AI-written and checked against the verified answer.