Lin is using the diagram to prove the statement, "If a parallelogram has one right
angle, it is a rectangle." Given that EFGH is a
parallelogram and angle HEF is right, which
reasoning about angles will help her prove
that angle FGH is also a right angle?
A. Corresponding angles are congruent when parallel lines are cut by a transversal.
B. Opposite angles in a parallelogram are congruent.
C. Vertical angles are congruent.
D. The base angles of an isosceles triangle are congruent.