Explanation:

Correct option is 1:58500.

- Let's assume the total sum lent is Rs x.

- The sum lent in two parts is in the ratio of 4:5.

- Let the first part be 4x/9 and the second part be 5x/9.

- Interest for the first part over 4 years at 8% per annum = (4x/9) * 8% * 4.

- Interest for the second part over 5 years at 8% per annum = (5x/9) * 8% * 5.

- Difference in interests = 4680.

Let's calculate:

- Interest from the first part = (4x/9) * (8/100) * 4 = (128x/900).

- Interest from the second part = (5x/9) * (8/100) * 5 = (200x/900).

- Difference = (200x/900) - (128x/900) = 4680.

- Solve: 72x/900 = 4680; x = 4680 * (900/72) = 58500.