If Rahim deposited the same amount of Rs. X in a bank at the beginning of successive 3 years and the bank pays simple interest of 5% per annum, then the amount at his credit at the end of 3rd year will be:

• A. Rs. 1261/400x
• B. Rs. 21/20x
• C. Rs. 26481/8000x
• D. Rs. 861/400x