What is the next step in the proof? Choose the most logical approach.
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Statement Reason 1. r || s given 2. ∠3≅∠7 ∠4≅∠8 For parallel lines cut by a transversal, corresponding angles are congruent. 3.
A. Statement: ∠1≅∠8 and ∠2≅∠7 Reason: Congruent Supplements Theorem
B. Statement: m∠3+m∠4=180° and m∠7+m∠8=180° Reason: Linear Pair Theorem
C. Statement: m∠3+m∠5=180° and m∠4+m∠6=180° Reason: definition of supplementary angles
D. Statement: ∠7≅∠6 and ∠8≅∠5 Reason: Vertical Angles Theorem

Question

What is the next step in the proof? Choose the most logical approach.
http://assets.openstudy.com/updates/attachments/52e7b708e4b05aea18ed93dc-random777-1390917427033-i.jpg 
Statement Reason 1. r || s given 2. ∠3≅∠7 ∠4≅∠8 For parallel lines cut by a transversal, corresponding angles are congruent. 3.
A. Statement: ∠1≅∠8 and ∠2≅∠7 Reason: Congruent Supplements Theorem 
B. Statement: m∠3+m∠4=180° and m∠7+m∠8=180° Reason: Linear Pair Theorem 
C. Statement: m∠3+m∠5=180° and m∠4+m∠6=180° Reason: definition of supplementary angles 
D. Statement: ∠7≅∠6 and ∠8≅∠5 Reason: Vertical Angles Theorem