Who among the following served as Prime Minister of Sikkim and later served as…

Concept

Sikkim's transition from a Himalayan monarchy to an Indian state created two distinct top political offices in quick succession. Under the monarchy the elected head of the popular ministry held the title Prime Minister of Sikkim, while after the 1975 merger with India the elected head of the new state government became the Chief Minister of Sikkim. A single leader bridged both titles across this transition.

Application

• In 1974 the popular movement against the Chogyal (monarch) brought Sikkim's elected ministry to power, and Kazi Lhendup Dorjee headed it as the Prime Minister of Sikkim (1974–1975).

• On 16 May 1975 Sikkim formally merged with India as its 22nd state. The Prime Minister's office was abolished and the same leader continued as the first Chief Minister of Sikkim, serving 1975–1979.

• Holding the PM office first and the CM office immediately after, Kazi Lhendup Dorjee is the one leader who served in both roles.

Cross-check / Contrast

• Tashi Namgyal and Sidkeong Tulku were Chogyals — the hereditary monarchs of Sikkim — not elected ministers, so neither held the PM-then-CM ministerial line.

• Nar Bahadur Bhandari became Chief Minister only later (from 1979 onward) and never held the pre-merger office of Prime Minister of Sikkim.

• Only Kazi Lhendup Dorjee satisfies the requirement of serving as Prime Minister and then as Chief Minister of Sikkim.