Explanation:

- Raj's initial income: Rs 45,000.

- Initial expenditure: Rs 33,000.

- Initial savings: Income - Expenditure = Rs 45,000 - Rs 33,000 = Rs 12,000.

Now, calculate the increased income and expenditure:

- Income increase: 20% of Rs 45,000 = Rs 9,000.

- New income: Rs 45,000 + Rs 9,000 = Rs 54,000.

- Expenditure increase: 12% of Rs 33,000 = Rs 3,960.

- New expenditure: Rs 33,000 + Rs 3,960 = Rs 36,960.

- New savings: Rs 54,000 - Rs 36,960 = Rs 17,040.

Percentage increase in savings:

- Increase in savings = Rs 17,040 - Rs 12,000 = Rs 5,040.

- Percentage increase = (Rs 5,040 / Rs 12,000) * 100 = 42%.

Therefore, the correct option is:

- Option 4: 42%