Your answer is C. Homeland Security
It would be the journal written by Christopher Columbus. (even though he didn't actually discover the new world, so he shouldn't get credit for it... but that's how it's taught in history.)
exploration and colonization of the colonies in America
Speculative investing weakened the stability of the stock market because people were "over-investing" in companies--meaning that that companies were becoming highly over-valued, which led to an economic "bubble" that eventually popped in the Crash of 1929.
