Membership first and foremost means holding all legal rights and privileges that stem from membership such as participating at the meetings, operations and decision-making processes of the organization on an equal footing. Organizations designate their membership criteria and application procedures in their statutes. Although founding members might have a certain degree of psychopolitical advantage, it is the full-membership that counts. Organizations, on the other hand, are also open to observer members which are sometimes called “contact States”, “dialog partners” etc..  As can be understood from the information given, the correct answer B.