Chad Spent a Couple Years in Prison for His Previous

Chad spent a couple years in prison for his previous charges. Once he was released he was still determined to harm his ex-girlfriend. Chad stalks his ex-girlfriend Megan and ends up killing her and burying her dead body in the Nevada desert.

A) Scott came out of criminal retirement and helped Chad bury Megan's body. Scott could be considered a/an:
B) solicitor.
C) aider and abettor.
D) s ex post facto conspirator.
E) conspirator.