Task: Question Answering
Input (English): Problem: if i walk at 4 km / h , i miss the bus by 10 minutes . if i walk at 5 km / h , i reach 5 minutes before the arrival of the bus . how far i walk to reach the bus stand ? 
Options: a ) 5 km , b ) 4.5 km , c ) 5 1 ⁄ 4 km / h , d ) can not be determined , e ) none of these
Output (English): a