Answer:
option D
Lines a and b are parallel and lines c and d are parallel.
Explanation:
Given in the question four lines a , b, c, d.
Prove one
If two parallel lines (a,b) are cut by a transversal(d), then corresponding angles m<7 and m<15 are congruent.
They are know as corresponding angles.
Hence lines a and b are parallel.
Prove two
If two parallel lines (c,d) are cut by a transversal(d), then corresponding angles m<13 and m<13 are congruent.
They are know as corresponding angles
Hence lines c and d are parallel