Task: Question Answering
Input (English): Problem: a person borrows rs . 5000 for 2 years at 4 % p . a . simple interest . he immediately lends it to another person at 5 % p . a for 2 years . find his gain in the transaction per year . 
Options: a ) 50 , b ) 150 , c ) 225 , d ) 112.5 , e ) 212.5
Output (English): a