What does A even mean?

I would start with the first half of the sentence: what does it mean to advance a synthesis of approaches? Since to synthesize means to bring two things together, or combine ideas, I would read that as the author supports combining two ideas. In context then, this is saying that the author is trying to combine two approaches to a specific issue. We very much have this in the passage, the first paragraph has the author tell us that they wish to combine the structural and cultural approaches to explaining the economic success of Chinese and Japanese immigrants. This seems like a 1-1 match for the passage. More generally, you want to tie the abstract words used in answer choices to concrete things in the passage. The question at issue is how two immigrant groups attained success in the face of discrimination, which we could reasonable describe as an issue (a mostly empty term). The synthesis is where the author tried to bring to gather the two approaches mentioned.