Task: Question Answering
Input (English): Problem: the number of the members of a club is more than 50 and less than 80 . when 5 people sit at a table , other people exactly divided to 8 - people groups ( 8 people sit at a table ) or 7 - people groups ( 7 people sit at a table ) . if the members are divided to 9 - people groups , how many people will be left ? 
Options: a ) 4 , b ) 5 , c ) 6 , d ) 7 , e ) 8
Output (English): d