Problem: in a rectangular coordinate system , what is the area of a rhombus whose vertices have the coordinates ( 0 , 3.5 ) , ( 8 , 0 ) , ( 0 , - 3.5 ) , ( - 8 , 0 ) ? 
Options: a ) 56 , b ) 88 , c ) 112 , d ) 116 , e ) 120
a