Simplify the following text for a Grade 8 native English-speaking person.
Original: The pay-per-view is part of WWE 's `` Big Four '' , along with WrestleMania , SummerSlam , and Survivor Series .
Simplified: The pay-per-view is a part of WWE 's `` Big Four , along with WrestleMania , SummerSlam , and Survivor Series .