Horizontal and parallel lines c and d are cut by transversal p. At the intersection of lines c and p, the uppercase left angle is angle 1 and the uppercase right angle is angle 2. At the intersection of lines d and p, the uppercase right angle is angle 3 and the bottom left angle is angle 4.
Which set of equations is enough information to prove that lines c and d are parallel lines cut by transversal p?
m∠1 = 81° and m∠2 = 99°
m∠3 = 99° and m∠4 = 99°
m∠2 = 99° and m∠4 = 99°
m∠4 = 81° and m∠1 = 81°