Final Answer:
Yahiya Khan lose power in December 20, 1971
Thus the correct option is (A).
Step-by-step explanation:
Yahya Khan lost power on December 20, 1971. This date marks a significant event in the context of the Bangladesh Liberation War when the Pakistani military, under Yahya Khan's leadership, faced defeat, leading to the creation of the independent state of Bangladesh. The loss of power by Yahya Khan was a consequence of the military defeat and the subsequent political developments in the region.
During the Bangladesh Liberation War, Yahya Khan's administration faced international condemnation for human rights abuses, particularly the widespread atrocities committed by the Pakistani military. The military campaign resulted in a humanitarian crisis and triggered a geopolitical shift, leading to the end of Yahya Khan's regime. The events of December 20, 1971, culminated in the surrender of Pakistani forces to the joint Indian and Bangladeshi forces, leading to the creation of the independent nation of Bangladesh. Yahya Khan's resignation and the loss of power marked the end of a tumultuous period in Pakistan's history and the beginning of a new chapter for the people of Bangladesh.
In summary, December 20, 1971, represents the date when Yahya Khan lost power, a critical moment in the aftermath of the Bangladesh Liberation War and the creation of Bangladesh as a sovereign nation.
Thus the correct option is (A).