I need help asap plz

Which of the following encouraged westward expansion? a.the government decreased the price of federal land. b.each of these represents actions taken to encourage westward expansion. c.the government decreased the price of federal land d.the second national bank lowered the cost of borrowing money (reduced interest rates)

Look at the graph. where p is price and q is quantity, what might cause a move from b to a?

Did the both the us and ussr have atomic weapons after 1949