Portfolio approach is considered an extension of the monetary approach because it

A、includestheabilitytoaccumulateforeignassetsbeyondcurrencies.
B、allowsthecentralbanktousemorethanjustbondstomaintaintheexchangerate.
C、includestheinternationalimpactsfromonecountryontoanother.
D、relatesthedomesticmoneystocktotheforeignmoneystock.