We know that : Vertically Opposite Angles of Two Intersecting Lines are Equal.
Here : The Pair of Vertically Opposite Angles are (2x + 50)° and (7x)°
⇒ (2x + 50)° = (7x)°
⇒ (7x)° - (2x)° = 50°
⇒ (5x)° = 50°
⇒ x = 10°
⇒ m∠AEB = (2x + 50)° = 2(10°) + 50° = (20° + 50°) = 70°
Option B is the Answer