Immediately after the death of Prime Minister Jawaharlal Nehru in 1964, who served as the acting Prime Minister of India until a new leader was chosen?

Introduction / Context:
When a sitting Prime Minister dies in office, there is often a brief transition period before a new leader is formally elected by the ruling party and appointed by the President. In India, such a situation arose after the death of Jawaharlal Nehru in 1964. This question asks you to recall the name of the person who acted as Prime Minister during that interim period, which is an important detail in modern Indian political history.

Given Data / Assumptions:

• The event is the death of Jawaharlal Nehru in 1964.
• The options are Lal Bahadur Shastri, Gulzari Lal Nanda, T. T. Krishnamachari, and Indira Gandhi.
• The question refers to an acting Prime Minister, not to the next full-term Prime Minister.
• We assume knowledge of the political sequence immediately after Nehru's death.

Concept / Approach:
When Nehru died in May 1964, there needed to be an interim arrangement until the Congress Party chose his successor. Gulzari Lal Nanda, who was then the senior Cabinet minister and had served as Home Minister, was appointed as acting Prime Minister. He held this position until Lal Bahadur Shastri was chosen as the next Prime Minister. Nanda later served as acting Prime Minister again in 1966 after the death of Lal Bahadur Shastri, which reinforces his association with this temporary role.

Step-by-Step Solution:
Step 1: Recall that Jawaharlal Nehru died in office on 27 May 1964.Step 2: Recognise that an acting Prime Minister had to be appointed immediately to ensure continuity of government.Step 3: Remember that Gulzari Lal Nanda was chosen as acting Prime Minister in 1964 and later again in 1966.Step 4: Lal Bahadur Shastri became the next full-term Prime Minister after Nehru, but he did not serve as the interim acting Prime Minister immediately upon Nehru's death.Step 5: Compare the options and identify Gulzari Lal Nanda as the correct answer.

Verification / Alternative check:
Standard modern history and polity texts mention that Gulzari Lal Nanda served twice as acting Prime Minister, once after Nehru and once after Shastri. This makes him unique in Indian political history. Lal Bahadur Shastri is remembered as Nehru's successor but not as the acting Prime Minister; he was appointed Prime Minister after the party's formal decision. Indira Gandhi became Prime Minister later, after Shastri's death. T. T. Krishnamachari was a senior leader but never Prime Minister. These cross-checks confirm that Nanda is the correct answer.

Why Other Options Are Wrong:

• Lal Bahadur Shastri: He became Prime Minister after Nehru but did not serve as the initial acting Prime Minister immediately upon Nehru's death.
• T. T. Krishnamachari: A prominent minister, but he never served as Prime Minister or acting Prime Minister.
• Indira Gandhi: She became Prime Minister after the death of Lal Bahadur Shastri, not immediately after Nehru's death.

Common Pitfalls:
Because Lal Bahadur Shastri is widely known as Nehru's successor, many candidates jump straight to his name and overlook the brief interim period. It is important to distinguish between the acting Prime Minister, who holds the position temporarily, and the substantive Prime Minister chosen by the party. A helpful memory aid is that Gulzari Lal Nanda is the only person to have been acting Prime Minister of India twice, making his name a frequent feature in exam questions.

Final Answer:
Immediately after Nehru's death, the acting Prime Minister of India was Gulzari Lal Nanda.