Task: Question Answering
Input (English): Problem: in a rectangular coordinate system , what is the area of a quadrilateral whose vertices have the coordinates ( 3 , - 1 ) , ( 3 , 8 ) , ( 12 , 2 ) , ( 12 , - 7 ) ? 
Options: a ) 69 , b ) 75 , c ) 81 , d ) 87 , e ) 93
Output (English): c