Task: Question Answering
Input (English): Problem: last year , for every 100 million vehicles that traveled on a certain highway , 80 vehicles were involved in accidents . if 4 billion vehicles traveled on the highway last year , how many of those vehicles were involved in accidents ? ( 1 billion = 1,000 , 000,000 ) 
Options: a ) 1600 , b ) 3200 , c ) 800 , d ) 400 , e ) 200
Output (English): b