QUESTION 15 Use the following environment for this question. The world consists of two large open economies, the US. and China. The US. economy is descbed by the following saving and investment curves: S( r) = 100+ 300r and I ( r) = 150 300r. China's economy is desciibed by the following saving and investment curves: S( r) = 100+ 200r and 1(r) =150 200r. Based on the equilibiium world interest rate, which of the following is true? A. The US. has a negative current account balance B. China has a negative current account balance