Explanation: Dr Rajendra Prasad was a key figure in the Indian Independence Movement and played a significant role in the struggle for India's freedom from British rule. He was a member of the Indian National Congress (INC), which was the primary political party leading the movement for independence. The INC was founded in 1885 and became the main platform for Indian nationalists to voice their demands for self-governance and eventually independence.
Dr Prasad's involvement with the INC began in the early 20th century. He was elected as the President of the INC in 1934 and again in 1939. His contributions to the party and the freedom struggle were substantial, and he was known for his legal expertise and his role in drafting the Indian Constitution. After India gained independence in 1947, he was elected as the first President of the Republic of India, a position he held until 1962.
The Indian National Congress was the dominant political force during the independence movement, and many of the leaders who played crucial roles in the struggle were members of this party. Other political parties such as the Bharatiya Janata Party (BJP) and the Communist Party of India (CPI) were formed much later and did not exist during the period of the Indian Independence Movement.
The Bharatiya Janata Party (BJP) was established in 1980, long after India had achieved independence. It is a right-wing political party that has its roots in the Rashtriya Swayamsevak Sangh (RSS), a Hindu nationalist organization. The Communist Party of India (CPI) was formed in 1925, but it did not play a significant role in the mainstream independence movement led by the INC.
Therefore, the correct answer is that Dr Rajendra Prasad joined the Indian National Congress during the Indian Independence Movement. This affiliation is a critical part of his political and historical legacy, reflecting his commitment to the cause of Indian independence and his significant contributions to the nation's struggle for freedom.