Quadrilateral EFGH has an exterior angle at vertex E measuring 120∘ and an exterior angle at vertex G also measuring 120∘. No other exterior angles are equal. Which of the following statements is correct?
(a) EFGH must be a kite.
(b) EFGH must be a parallelogram.
(c) EFGH has exactly one pair of equal opposite interior angles.
(d) EFGH is necessarily an isosceles trapezium.