During the $2008-2009$ recession, the average P$/$E ratio of firms in the U$.$S$.$ stock market reached an extraordinarily high level because $\_\_\_\_\_\_\_\_.$

Question $28$ options:

A$)$ investors believed short$-$term growth prospects for U$.$S$.$ firms were extraordinarily good at that time

B$)$ stock prices generally boomed during the recession

C$)$ earnings per share were unusually low during the recession

D$)$ investors believed long$-$term growth prospects coming out of the recession were not very good