ACI Dealing Certificate (#408)

Which of the following definitions of a nostro account is correct?

A nostro account is an account held by a bank in a foreign country in the banks domestic currency.
A nostro account is an account held by a bank in a foreign country for cash collateralising OTC derivative positions with banks in that country.
A nostro account is an account held by a bank in a foreign country in the currency of that country.
A nostro account is an account held by a bank in its home country in a foreign currency.