Daniel is constructing a fence that consists of parallel sides line AB and line EF. Complete the proof to explain how he can show that m∠GKB = 120° by filling in the missing justifications. A. 1. Alternate Interior Angles Theorem; 2. Definition of Congruence B. 1. Alternate Exterior Angles Theorem; 2. Substitution Property C. 1. Definition of Congruence; 2. Alternate Interior Angles Theorem D. 1. Substitution Property; 2. Alternate Exterior Angles Theorem