Which of the Following Statements Best Exemplifies the Concept of "Contract

Which of the following statements best exemplifies the concept of "contract" in terms of parole?

A) The government could keep the inmate incarcerated, but instead extends the privilege of release.
B) Even though the offender is released from prison, he or she is still in the custody of the state.
C) The parolee agrees to abide by certain conditions in exchange for release.
D) The offender is still the responsibility of the government even though he or she is released.
E) The parole officer agrees to care for the parolee in exchange for a salary.