I'm down too!

@AdrianBurger This is also the only question I missed in this passage and I made the same error since their proposal speaks about migration in general terms and then it gets applied to the Great Migration. But their purpose in giving the proposal in the first place is to explain why the Great Migration lasted. They already know some reasons why people migrate ("economists typically assumed that people migrate if..." and "Previous research suggests..."). They then apply those known reasons to their questions about the Great Migration.

I thought answer choice C was making some joke about how the caffeine in coffee made the blood cells caffeinated and work faster and was like pft that's ridiculous no way