The British decided to leave India after the second world war.

Reasons for the British Leaving India after the Second World War:

1. Indian Nationalist Movement:
- The Indian nationalist movement gained significant momentum during the first half of the 20th century, demanding independence from British rule.
- Leaders like Mahatma Gandhi, Jawaharlal Nehru, and Subhas Chandra Bose played crucial roles in organizing mass protests and advocating for self-rule.
- The nationalist movement became even stronger during the Second World War as Indians demanded freedom in exchange for their support in the war effort.

2. Impact of the Second World War:
- The Second World War had a profound impact on the British Empire, including India. It weakened the British economically, politically, and militarily.
- Britain had to divert significant resources to the war effort, which left them financially strained.
- The war also resulted in the loss of British colonies in Southeast Asia, such as Burma and Malaysia, which further weakened their hold on India.

3. Indian National Army and Subhas Chandra Bose:
- Subhas Chandra Bose, a prominent Indian nationalist leader, formed the Indian National Army (INA) with the help of the Japanese during the Second World War.
- The INA fought against the British alongside the Japanese forces in Southeast Asia.
- The INA's actions and Bose's leadership inspired many Indians and created a sense of unity and resistance against British rule.

4. Labour Party Government in Britain:
- The Labour Party came to power in Britain after the Second World War, led by Clement Attlee.
- The Labour Party was more sympathetic to the Indian nationalist cause and believed in granting independence to India.
- Attlee's government realized that maintaining control over India was becoming increasingly difficult and decided to initiate the process of granting independence.

5. Mountbatten Plan and Indian Independence:
- In 1947, Lord Mountbatten was appointed as the last Viceroy of India and was given the task of overseeing the transfer of power.
- He devised a plan to divide British India into two separate nations - India and Pakistan, based on religious lines.
- India and Pakistan gained independence on August 15, 1947, marking the end of British rule in the Indian subcontinent.

Overall, the combination of the Indian nationalist movement, the impact of the Second World War, the formation of the Indian National Army, the change in the British government, and the Mountbatten Plan led to the British decision to leave India after the Second World War.

India 1947 mai independent hua means British ne india 1947 mai chhoda and second world war 1947 se phle hi ho gaya tha ,so answer is B