“Sup？ What up？ or Whazzup / Whassup？” These greetings are abbreviations of（）.

“Sup？ What up？ or Whazzup / Whassup？” These greetings are abbreviations of（）.
A.“what’s up？”
B.What’s matter？
C.What are you doing？
正确答案：“what’s up？”