Explanation:

To find the compound interest on Rs20,000 for 9 months at a rate of 4% per annum with quarterly compounding, we can use the formula for compound interest:

- Formula: A = P(1 + r/n)^(nt)

- P = Principal amount = Rs20,000

- r = Annual interest rate = 4% = 0.04

- n = Number of times interest is compounded per year = 4 (quarterly)

- t = Time in years = 9 months = 0.75 years

- Calculate:

- A = 20000(1 + 0.04/4)^(4 * 0.75)

- A = 20000(1 + 0.01)^(3)

- A = 20000(1.030301)

- Final Amount: Approximately Rs20606.02

- Compound Interest: A - P = 20606.02 - 20000 = Rs606.02

- Option 2: Rs606.02

Correct Answer: Option 2 - Rs606.02