Select the correct answer. Given: BC || DE, and ∠GAC ≅ ∠AFD. Prove: Statement Reason 1. ∠GAC ≅ ∠AFD given 2. ∠GAC ≅ ∠AFE For parallel lines cut by a transversal, corresponding angles are congruent. 3. 4. ∠AFD and ∠AFE are supplementary. Linear Pair Theorem 5. m∠AFD = m∠AFE = 90° If two congruent angles are supplementary, then each angle is a right angle. 6. definition of perpendicular lines What is the missing step in the proof? A. Statement: ∠GAC and ∠GAB are supplementary. Reason: Linear Pair Theorem B. Statement: ∠AFE ≅ ∠AFD Reason: Transitive Property of Equality C. Statement: ∠GAC ≅ ∠BAF Reason: Vertical Angles Theorem D. Statement: ∠GAC and ∠AFD are supplementary. Reason: Linear Pair Theorem