The correct answer is option B, which states that the boundary commission headed by Radcliff demarcated the boundaries between the two Dominions of India and Pakistan.

Explanation:

1. The Partition of India:
- The partition of India was a significant event that took place in 1947, leading to the creation of two separate nations - India and Pakistan.
- The partition was a result of the Indian Independence Act of 1947, which proposed the division of British India into two dominions, one with a Hindu majority (India) and the other with a Muslim majority (Pakistan).
- The partition was accompanied by widespread violence, communal riots, and mass migration, resulting in the displacement and loss of lives of millions of people.

2. The Radcliff Boundary Commission:
- In order to determine the boundaries between India and Pakistan, the British government appointed a boundary commission headed by Sir Cyril Radcliff, a British lawyer and judge.
- The commission was tasked with the demarcation of the boundary between the two new nations based on religious demographics and other factors.
- Radcliff and his team were faced with the daunting challenge of drawing the borders within a short period of time, leading to several contentious decisions and disputes.

3. Demarcation of Boundaries:
- The Radcliff Boundary Commission relied on various factors such as religious demographics, administrative boundaries, and geographical considerations to demarcate the boundaries between India and Pakistan.
- The commission examined maps, census data, and consulted with local leaders and officials to make their decisions.
- The demarcation process was complex and involved drawing lines through areas with mixed populations, resulting in the displacement of communities and the division of regions.
- The commission faced criticism for the lack of precision and the arbitrary nature of some of its decisions, leading to ongoing border disputes between India and Pakistan.

4. Aftermath and Legacy:
- The demarcation of boundaries by the Radcliff Commission had far-reaching consequences for the newly formed nations of India and Pakistan.
- It resulted in the division of Punjab and Bengal provinces, which witnessed widespread violence and mass migration.
- The partition also led to the displacement of millions of people, communal tensions, and ongoing conflicts over disputed territories.
- The Radcliff Line, the boundary drawn by the commission, continues to be a source of tension between India and Pakistan, with various disputes and conflicts arising along the border over the years.

In conclusion, the boundary commission headed by Radcliff was responsible for demarcating the boundaries between the two Dominions of India and Pakistan during the partition in 1947. The commission's decisions and the resulting Radcliff Line have had a profound impact on the history and geopolitical landscape of the region.