The correct answer is option 3: 1919. The System of Dyarchy was introduced in India through the Government of India Act of 1919, which was also known as the Montagu-Chelmsford Reforms.

Dyarchy means dual rule, and it was a mechanism to divide the power between the elected Indian representatives and the British officials. According to this system, certain subjects such as finance, law, and order were placed under the direct control of British officials (called reserved subjects), while other subjects were placed under the control of the Indian representatives (called transferred subjects).

However, it is important to note that this system was short-lived and was abolished in 1937 with the introduction of full responsible government in certain provinces through the Government of India Act of 1935.