The USD trade$-$weighted dollar index $($TWI$)$ is a weighted average of the value of the US dollar in foreign exchange against the currencies of the US's major trading partners. The TWI is used to determine the dollar's purchasing value and summarizes the effects of dollar appreciation and depreciation against foreign currencies. During the past five years the TWI index has

A$.$ Appreciated by ~ $8\%$

B$.$ Depreciated by ~ $12\%$

C$.$ Depreciated by ~ $75\%$

D$.$ Appreciated by ~ $90\%$