The correct answer is (a) Lord Rippon.

Lord Rippon was the Viceroy of India from 1880 to 1884. During his tenure, he introduced a number of reforms, including financial decentralization. This involved transferring power over Taxation and expenditure from the central government to the provinces. This was a significant step towards greater self-government for India.

Lord Dalhousie was the Viceroy of India from 1848 to 1856. He is best known for his policy of annexation, which saw the British take control of a number of Indian states. He also introduced a number of reforms, including the introduction of railways and telegraphs. However, he did not introduce financial decentralization.

Charles Metcaff was the Governor of Madras from 1832 to 1837. He is best known for his work on education, which saw the establishment of a number of schools and colleges in Madras. However, he did not introduce financial decentralization.

Lord Mayo was the Viceroy of India from 1869 to 1872. He is best known for his policy of conciliation, which sought to improve relations between the British and the Indian people. However, he did not introduce financial decentralization.