Which equation would be used in proving that the diagonals of parallelogram abcd bisect each other? a) (3-1)2 + (2-0)2 = (1-3)2 + (0+4)2 b) (3+1)2 + (2+0)2 = (1+3)2 + (0-4)2 c) (-1-1)2 + (4-0)2 = (1-3)2 + (0+4)2 d) (-1+1)2 + (4+0)2 = (1+3)2 + (0-4)2