Mizuho Securities Lost $225 Million When

Mizuho Securities lost $225 million when

A) hackers broke into its trading system and raided the accounts of 10,000 of its most important customers.
B) a bug in its billing system caused it to send out improper invoices to 10,000 of its most important customers.
C) a bug in its currency trading system caused it to sell yen and purchase dollars when it should have purchased yen and sold dollars.
D) it tried unsuccessfully to automate the Tokyo Stock Exchange.
E) one of its employees mistyped a sell order, and a bug in the Tokyo Stock Exchange trading program made it impossible to cancel the order.