Bangladesh was a part of Pakistan from ______.

The correct answer is Option (4) → 1947 - 1971

The period from 1947 until 1971 saw East Pakistan as part of the larger Pakistani state. However, tensions and disparities arose between West Pakistan and East Pakistan due to various factors, including economic, linguistic, and cultural differences, as well as political marginalization of the Bengali population in East Pakistan by the dominant West Pakistani establishment.

The situation escalated, leading to the Bangladesh Liberation War in 1971. During this conflict, East Pakistan fought for its independence from West Pakistan. The war concluded with the victory of the Bengali nationalists, supported by India, leading to the creation of the independent state of Bangladesh on December 16, 1971.

Therefore, Bangladesh was a part of Pakistan from 1947 until 1971, after which it became an independent nation.