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.