Which one of the following cases or events can be considered as resulting from an opera$-$

tional risk?

A$)$ A bank reports losses on a diversified portfolio of stocks during the stock market de$-$

cline

B$)$ The bank becomes embroiled in a high$-$profile lawsuit with a customer that accuses it

of improper selling practices

C$)$ The bank reports the loss of $$1\mathrm{.}5$ billion due to rises in interest rates

D$)$ A US investor makes a loss as Japanese Yen depreciates relative to the dollar

please explain..