Concept:The Khulafa'ul-Rashidun are the first four rightly guided caliphs of Islam.
Explanation:The four rightly guided caliphs are Abu Bakr, Umar, Uthman, and Ali.
They ruled in succession after the death of the Prophet Muhammad (SAW).
Mu'awiyah bn Abi Sufyan became a caliph later, but he is not counted among the Khulafa'ul-Rashidun.
Therefore, among the options given, Mu'awiyah is the one who is not a rightly guided caliph.
Answer:Option A: Mu'awiyah bn Abi Sufyan.