From my previously gained knowledge from my Japanese classes, the answer would be D. Because Japan didn't really that much of a population boom until the 20th century because they whole island was not yet inhabited. They didn't really feel like spreading Buddhism because it didn't become a popular religion until the 20th century, and the US had nothing to do with Japans wanting of more land. They gained land mainly from China, so the long-standing rivalry between China and Japan would be the best answer.
Greg Heffley as he attempts both to deal with his Grandpa's moving in, and dealing without modern comforts while attending Hardscrabble Farm. Greg gets roped into volunteering at the park as well. is the answer to the question