Please help! Use the figure to answer the question that follows:

First Picture

The two-column proof below describes the statements and reasons for proving that corresponding angles are congruent:

2nd Picture

What is the missing statement for step 7?

m∠SQV + m∠VQT = 180°

m∠VQT + m∠ZRS = 180°

∠SQV + m∠VQT = m∠VQT + m∠ZRS

m∠SQV + m∠SQT = 180°