A 4-sided figure has 4 corners labeled E, G, D, C starting from the top-left corner and going clockwise. A line cuts through the shape from point C to point G and contains point F. Another line cuts through the shape from E to point F. Angle C E G is a right angle.
Based on the diagram, which reason justifies this statement?

If ∠CEF is complementary to ∠DCF, then
∠DCF ≅ ∠FEG.

Complements of the same angle are congruent.
Complements of congruent angles are congruent.
Supplements of the same angle are congruent.
Supplements of congruent angles are congruent.