In Which of the Following Cases Did the Supreme Court

Multiple Choice

In which of the following cases did the Supreme Court establish that parole revocation and, by implication, probation revocation is to be a two-stage process? In the first stage, there must be an informal, preliminary inquiry to establish probable cause that a violation has occurred. In the second stage (assuming that probable cause is established in the first stage) , there must be a formal court hearing to determine if the violation warrants revocation.

A) Gagnon v. Scarpelli
B) Morrissey v. Brewer
C) Griffin v. Wisconsin
D) Mempa v. Rhay