The reference reporting population shall comprise the following reporting agents: (a) legal and natural persons falling within the sub-sectors 'central bank`, 'other monetary financial institutions` and 'other financial intermediaries, except insurance corporations and pension funds` as described in Annex B and residing in a Member State, to the extent necessary to fulfil the ECB's statistical reporting requirements in the field of money and banking statistics and payment systems statistics; (b) post office giro institutions, to the extent necessary to fulfil the ECB's statistical reporting requirements in the field of money and banking statistics and payment systems statistics; (c) legal and natural persons residing in a Member State, to the extent that they hold cross-border positions or carry out cross-border transactions and that statistical information relating to such positions or transactions is necessary to fulfil the ECB's statistical reporting requirements in the field of balance of payments statistics or the International Investment Position; (d) legal and natural persons residing in a Member State, to the extent that statistical information relating to the securities or the electronic money issued by them is necessary to fulfil the ECB's statistical reporting requirements.