A. Liked M&M candies

B. Slang for Detroit

C. Record label name

D. Marshall Mathers

Details of Why is Eminem called Eminem:

When Eminem started rapping at the age of 14, Mike Ruby was his collaborator. Eminem’s real name is Marshall Mathers. Originally known as “Manix,” the duo later adopted the moniker M&M. He eventually started to become more independent, but he enjoyed the moniker M&M. As a result, he realized he could maintain it merely with his name Marshall Mathers and changed it to Eminem to distance himself from the candy.