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) Chad's previous prison cell-mate Scott drove Chad to Megan's house with the intent of helping Chad dispose of the body. Scott helped Chad plan the murder, supplied him with the weapon, and helped bury her in the desert. Chad could be considered a/an:
B) partner in crime.
C) accomplice. ​
D) criminal acquaintance.
E) unwilling accomplice.