Option 1: 26th January, 1950 - This date is incorrect. 26th January, 1950 is the date when the Constitution of India came into effect, not when its drafting was completed.

Option 2: 26th December, 1949 - This date is incorrect. The drafting of the Constitution was completed before 26th December, 1949.

Option 3: 26th November, 1949 - This is the correct answer. The drafting of the Indian Constitution was completed on 26th November, 1949. The Constituent Assembly of India took almost 3 years to finalize the Constitution, starting in December 1946 and ending with the adoption of the Constitution on 26th November, 1949.

Option 4: 30th November, 1949 - This date is incorrect. The drafting of the Constitution was completed on 26th November, 1949, not on 30th November, 1949.

In conclusion, the correct answer is option 3: 26th November, 1949.