7. Recently, a growing labor shortage has been causing Chinese wages to rise. If this trend continues, there is a possibility that the external economy industries currently dominated by China may shift to Vietnam. In this light, consider the situation illustrated in Slide 70. a. How would ACChina shift (i.e., upward or downward) due to the rise in wages? b. If P1 continues to denote the price of Chinese buttons, what condition between P1 and C0 must be satisfied for button production to remain in China?