Explanation:

- Gulzari Lal Nanda was an acting Prime Minister of India twice but not in 1978. He served temporarily after the deaths of Jawaharlal Nehru in 1964 and Lal Bahadur Shastri in 1966.

- Charan Singh was the Prime Minister of India later, in 1979-1980, after Morarji Desai resigned.

- Morarji Desai was the Prime Minister of India in 1978. He became the Prime Minister in 1977 after the Emergency period and led the Janata Party government.

- Lal Bahadur Shastri served as Prime Minister from 1964 until his untimely death in 1966 and was not in office in 1978.

.