NO.PZ2020021002000228
问题如下：
At the peak of the GFC in September 2008, which of the following events did not occur
选项：
A.Lehman Brothers declared bankruptcy.
B.Morgan Stanley and Goldman Sachs were converted to bank holding companies
C.Fannie Mae and Freddie Mac were officially designated government sponsored enterprises.
D.AIG was brought back from the brink of collapse.
解释：
Fannie Mae and Freddie Mac were already GSEs. They were nationalized.
房利美和房地美已经是政府支持企业。
麻烦解释一下事件怎么发生的呗
