The Cause of the October 19,1987 Stock Market Crash

The cause of the October 19,1987 stock market crash

A) is related to actions taken on that date by the Federal Reserve Bank.
B) has been identified as the result of major internet company announcements on the prior day.
C) resulted from losses in international markets.
D) has yet to be determined.
E) was the result of regulatory changes that were implemented that morning.