Correct Option: A

Dyarchy was introduced as a constitutional reform by Edwin Samuel Montagu (secretary of state for India, 1917–22) and Lord Chelmsford (viceroy of India, 1916–21). It marked the first introduction of the democratic principle into the executive branch of the British administration of India. Though much-criticized, it signified a breakthrough in British Indian government and was the forerunner of India’s full provincial autonomy (1935) and independence (1947).