Determine whether each quadrilateral is a parallelogram. Justify your answer. (6 points total/1 point each)
A. Yes, one pair of opposite sides is both parallel and congruent.
B. Yes, both pairs of opposite sides are parallel.
C. Yes, both pairs of opposite sides are congruent.
D. Yes, diagonals bisect each other.
E. Yes, both pairs of opposite angles are congruent.
F. Not a parallelogram.