(A) Twice a year
(B) Once a month
(C) ** Once a year
(D) Twice a month
EXPLANATIONS BELOW
Concept note-1: -The Assembly met at least once a year in ordinary session, normally in September. If necessary, it could meet at any moment at the request of one or more members if approved by the majority of Member States.
Concept note-2: -The main organs of the League of Nations were the General Assembly, the Council and the Secretariat. The General Assembly, which met once a year, consisted of representatives of all the member states and decided on the organization’s policy.
Concept note-3: -The main aims of the organisation included disarmament, preventing war through collective security, settling disputes between countries through negotiation and diplomacy, and improving global welfare.