The correct answer is: A. 20th January, 1913.
The first sitting of the Council was convened on 20th January, 1913. The Council was established by the Government of India Act, 1919, which also introduced dyarchy in India. The Council was a legislative body consisting of both elected and nominated members. The elected members were chosen by the provincial legislative councils, while the nominated members were appointed by the Governor-General. The Council had limited powers, but it was an important step in the development of representative government in India.
Option B is incorrect because the first sitting of the Council was not convened on 20th January, 1914.
Option C is incorrect because the first sitting of the Council was not convened on 20th January, 1920.
Option D is incorrect because the first sitting of the Council was not convened on 20th January, 1918.