The state seeks to revoke the parole of an individual who served three years of a ten-year sentence for burglary, then was released on parole. A parolee has a right to cross-examine witnesses from whom the parole officer has obtained information supporting the revocation determination: /a. in all cases; /b. unless the hearing officer determines that the informant who provided information of parole violations would be endangered if identified; /c. when the alleged parole violator decides that such cross-examination may be useful in deciding the parolee's case; /d. such right is never accorded a parolee; /e. none of the above.