Task: Question Answering
Input (English): Problem: the s . i . on a certain sum of money for 2 years at 6 % per annum is half the c . i . on rs . 4000 for 2 years at 10 % per annum . the sum placed on s . i . is ? 
Options: a ) 2197 , b ) 1267 , c ) 3500 , d ) 2267 , e ) 1262
Output (English): c