Final answer:
Bangladesh gained independence from Pakistan as a result of a war, specifically the Indo-Pakistan War of 1971, supported by the Indian military, leading to the creation of Bangladesh in 1972.
Step-by-step explanation:
How did Bangladesh gain freedom from Pakistan?
Bangladesh gained its independence from Pakistan through a war known as the Indo-Pakistan War of 1971. Initially, after the end of British colonial rule in 1947, Pakistan was created as one state with two geographically and ethnically separate regions: West Pakistan and East Pakistan. Tensions between the two wings grew, especially after the central government's inadequate response to a devastating cyclone that hit East Pakistan in 1970. The situation escalated into a full-blown civil war that lasted for about three months in 1971. The conflict ended when East Pakistan, with the support of the Indian military, successfully fought to become an independent nation, and thus Bangladesh was born in 1972.
So, the correct option regarding how Bangladesh obtained its independence from Pakistan is Option 4: War.