Explanation:
(e)
because BCDF is a parallelogram, it means that F D = B C = 4.
and F B = D C = 6.
because EDCF is a parallelogram, it means that D C = E F = 6.
that means that E F = F B = 6, so the diagonal E B of ABDE is intersected by the other diagonal A D in the middle at F.
because ABCF is a parallelogram, it means that A F = B C = 4.
that means that A F = F D = 4, so, also the diagonal A D of ABDE is intersected by the other diagonal E B in the middle at F.
when 2 line segments E B and A D intersect each other that way, that makes them the diagonals of a parallelogram.
therefore, ABDE is a parallelogram.