Who proposed in 1963 that all senior Congressmen should resign from office to make way for younger party workers?

The correct option is K. Kamaraj.

Historical Context:
In the early 1960s, the Indian National Congress was facing internal challenges, including a decline in public support, factionalism, and a growing perception that senior leaders were more interested in holding governmental power than doing grassroots work. To address this crisis and revitalize the party, K. Kamaraj, who was then the Chief Minister of Madras State (now Tamil Nadu), proposed a strategic initiative in 1963.

The Kamaraj Plan:
This proposal, which became widely known as the Kamaraj Plan, suggested that all senior Congress politicians holding ministerial offices in both the Central Cabinet and State Governments should voluntarily resign from their posts. Instead of holding government portfolios, these seasoned leaders were to devote their full time and energy to organizational work to rebuild the party's connection with the general public.

Objectives and Impact:
The primary goals of this plan were to:
1. Make way for younger party workers to assume leadership roles and gain administrative experience.
2. Counter the perception that Congress leaders had become detached from the public and obsessed with power.
3. Re-inject energy into the party's organizational machinery ahead of future elections.

Prime Minister Jawaharlal Nehru accepted the plan, leading to the resignation of six Union Cabinet ministers (including Lal Bahadur Shastri, Morarji Desai, and Jagjivan Ram) and six State Chief Ministers. K. Kamaraj himself resigned as Chief Minister of Madras and was subsequently elected as the President of the Indian National Congress to lead the organizational revival.