Two distinct lines, l and m, are each perpendicular to the same line n. Explain why l and m are parallel lines. A. If alternate interior angles are congruent, then lines are parallel (AI Thm)

B. If corresponding angles are congruent, then lines are parallel (Corr Angles Thm)

C. If same side interior angles are supplementary, then lines are parallel (SSI Thm)

D. If two lines are parallel to a 3rd line, then the lines are parallel.

E. All of the above