The correct answer is B. 1966.
The United Nations General Assembly terminated South Africa’s mandate over Namibia in 1966. South Africa had been administering Namibia as a League of Nations mandate since 1920, but the UN had never recognized South Africa’s authority over the territory. In 1966, the General Assembly voted to terminate South Africa’s mandate and to establish a UN Council for Namibia to administer the territory until it could achieve independence. South Africa refused to comply with the UN resolution, and continued to administer Namibia until 1990, when it finally granted independence to the country, which was renamed Namibia.
Option A is incorrect because the UN General Assembly did not terminate South Africa’s mandate over Namibia in 1968.
Option C is incorrect because the UN General Assembly did not terminate South Africa’s mandate over Namibia in 1969.
Option D is incorrect because the UN General Assembly did not terminate South Africa’s mandate over Namibia in 1965.