445. In which of the following years, the membership of the Security Council was increased from 11 to 15 (under Article 23)?

✅ The correct answer is option B.
In 1965, the membership of the Security Council was increased from 11 to 15 (under Article 23). Expansion of the UN Security Council from 11 to 15 members, with the supermajority required for action being increased from 7 to 9 votes.