Question: What is the stage name of the American rapper from Michigan, who was a member of Funky Cowboys, Good Sqwad, and most notably for a group in which half the members made a guest appearance on the debut solo album 'The People vs' by Trick-Trick?
Sentence (from "Proof (rapper)"): During his career, he was a member of the groups 5 Elementz, Funky Cowboys, Promatic, Goon Sqwad and most notably, D12.
Relevant evidence: Yes