Explanation:

- Social Banking:

- This was a policy initiative aimed at extending financial services and credit to the rural and underbanked segments of society.

- It meant increasing the reach of financial institutions to ensure social justice and development.

- Multi-Agency Approach:

- Introduced alongside social banking, this strategy involved having multiple institutions, like commercial banks, cooperatives, and regional rural banks, to provide rural credit.

- It capitalized on the strengths of different financial entities to reach a larger rural population.

- Option 4, "None of these," is not correct because India did initiate significant changes in 1969 to improve rural credit.

- Option 3: Both a and b

- This is the correct answer because India adopted both social banking and a multi-agency approach to meet rural credit needs.