_________  is an Act of the Parliament of the United Kingdom that partitioned British India into two new independent dominions of India and Pakistan in 1947.

Indian Independence Act

The correct answer is Option 2 - Indian Independence Act

Indian Independence Act 1947:

The Indian Independence Act of 1947 was a pivotal piece of legislation passed by the British Parliament that marked the end of British rule in India.
The act established the creation of two independent dominions: India and Pakistan. This decision was based on the Mountbatten Plan, which aimed to address the growing religious tensions between Hindus and Muslims.
August 15, 1947, was set as the official date of independence for both India and Pakistan.