Explanation:

- Charulata withdrew Rs 10,000 at the end of each quarter: June, September, December, and March.

- Total drawings = 10,000 X 4 = 40,000

- Interest on drawings is calculated based upon the average period of usage for the amount withdrawn.

- When date of drawing is not mentioned average period is taken 6 months

  40,000 X 9/100 X 6/12 = 18,000

$$

- Options given are:

- 1,350

- 2,250

- 900

- 1,800

- Option 4: 1,800 is the correct calculation.