Which of these was not part of the three-country Central African Federation that existed from 1953 to 1963?

The Central African Federation consisted of three southern African territories: the self-governing British colony of Southern Rhodesia and the British protectorates of Northern Rhodesia and Nyasaland; it was also known as the Federation of Rhodesia and Nyasaland.

This colonial federation was established on 1 August 1953, with a Governor-General as the Queen's representative at the centre.

The federation officially ended on 31 December 1963. In 1964, shortly after the dissolution, Northern Rhodesia and Nyasaland became independent under the names Zambia and Malawi, respectively. In November 1965, Southern Rhodesia unilaterally declared independence from the United Kingdom as the state of Rhodesia. When minority white rule ended Rhodesia became Zimbabwe.

Tanganyika was not part of the Central African Federation. It lay to the north-east of Northern Rhodesia and was a separate sovereign state that existed until 1964. Tanganyika adopted a new constitution in 1962 that abolished the monarchy, with the National Assembly drastically revising the new Constitution to favour a strong executive branch of government, namely a president. Tanganyika then became a republic within the Commonwealth, with Julius Nyerere as President. In 1964 Tanganyika and Zanzibar were united to become the present-day country known as Tanzania.