(B) False.
To determine if the points form a parallelogram,we calculate the lengths of the sides using the distance formula: $d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2}$.
$AB = \sqrt{(6-4)^2 + (4-3)^2} = \sqrt{2^2 + 1^2} = \sqrt{5}$
$BC = \sqrt{(5-6)^2 + (-6-4)^2} = \sqrt{(-1)^2 + (-10)^2} = \sqrt{1 + 100} = \sqrt{101}$
$CD = \sqrt{(-3-5)^2 + (5 - (-6))^2} = \sqrt{(-8)^2 + 11^2} = \sqrt{64 + 121} = \sqrt{185}$
$DA = \sqrt{(4 - (-3))^2 + (3-5)^2} = \sqrt{7^2 + (-2)^2} = \sqrt{49 + 4} = \sqrt{53}$
In a parallelogram,opposite sides must be equal ($AB = CD$ and $BC = DA$). Since all sides are unequal,the given points do not form a parallelogram.