During the 1920s,
the U.S. stock market had undergone rapid expansion, reaching its peak in August 1929, and by then the production already declined, and unemployment rose, leaving the stocks in great excess of their real value.
A. the U.S. stock market had undergone rapid expansion, reaching its peak in August 1929, and by then the production already declined, and unemployment rose
B. the production had already declined with the rising unemployment, by the time the US stock market underwent rapid expansion reaching its peak in August 1929
C. the U.S. stock market underwent rapid expansion and thereby reached its peak in August 1929, and by then the production had already declined, and unemployment had risen
D. the U.S. stock market reached its peak in August 1929 after undergoing rapid expansion, and by that time the production had already declined, and unemployment had risen
E. with the production already declined and the unemployment already rising, the US stock market underwent rapid expansion, reaching its peak in August 1929