Option 1: Man set foot on the Moon for the first time. This event occurred on July 20, 1969, and is not related to the important events of Dec. 16, 1971.

Option 2: Liberation of Bangladesh. This is the correct answer. On Dec. 16, 1971, the Pakistani Army surrendered to the Indian Army, leading to the liberation of Bangladesh. This event marked the end of the Bangladesh Liberation War and the formation of the independent nation of Bangladesh.

Option 3: Outbreak of hostilities between India and Pakistan. This event actually took place before Dec. 16, 1971. The Indo-Pakistani War started on Dec. 3, 1971, and lasted until Dec. 16, 1971. It ultimately led to the liberation of Bangladesh.

Option 4: India accorded recognition to the Republic of Bangladesh. This event is related to the liberation of Bangladesh but is not the most important event of Dec. 16, 1971. The recognition of Bangladesh by India took place on Dec. 6, 1971, and was an important diplomatic move, but the surrender of the Pakistani Army on Dec. 16, 1971