Lord Mayo began financial decentralisation — option 1.

The reform of 1870. Until then every rupee of revenue was collected and every rupee of expenditure sanctioned centrally, so a provincial government had neither money of its own nor any reason to economise. Mayo’s resolution of 1870 changed that: the provinces were given a fixed annual grant from the centre out of which they had to meet the whole cost of certain departments — police, jails, education, medical services and roads — and were permitted to raise some local taxes. Anything saved they kept; any excess they had to find themselves.

Why it was done. The motive was not liberal but fiscal. The costs of the Mutiny, of the Afghan wars and of famine relief had left the government of India in chronic deficit, and central control had produced no incentive anywhere to keep spending down. Making provinces bear the consequences of their own decisions was expected to enforce economy — and it did.

Why option 3 is the sharpest distractor. Ripon carried the process considerably further, and his name is the one most associated with decentralisation in general because of the local self-government resolution. But that resolution concerned municipal and district boards, and it came twelve years later; the question asks who began the decentralisation of the economic structure, and that is Mayo.

Mayo’s other measures : the first regular Census of India was decided upon in his time and taken in 1872, and the Department of Agriculture and Commerce was established. He was assassinated in the Andamans in 1872, the only Viceroy killed in office.

Hence, the answer is Mayo.