Refer to Figure 8minus2. Which of the following events could cause the upward shift of the AS curve? Question content area bottom Part 1 A. a massive drought that reduces agricultural output B. improvements in communications technology C. a major discovery of new oil reserves that will increase the world supply D. a recession in the country that reduces net exports E. a decrease in business confidence that reduces desired investment Which of the following events could cause the upward shift of the AS curve