Nitin borrowed some money at the rate of 6% p.a. for the first three years, 9% p.a. for the next five years and 13% p.a. for the period beyond eight years. If the total interest paid by him at the end of eleven years is Rs. 8160, the money borrowed by him (in Rupees) was?

• A. Rs. 12000
• B. Rs. 6000
• C. Rs. 8000
• D. Rs. 10000