Problem: in a rectangular axis system , what is the area of a parallelogram with the coordinates : ( 4,4 ) , ( 7,4 ) , ( 5,9 ) , ( 8,9 ) ? 
Options: ['a ) 21 .', 'b ) 28 .', 'c ) 5 .', 'd ) 49 .', 'e ) 52 .']
c