The idea is more like the first, but not exactly. Prisoners can have part of their sentence shortened as a reward for good behaviour. After that, they can be released 'on parole' - with special conditions and restrictions. Prisoners have their terms reconsidered regularly. At this prison, presumably, the Parole Board meets one a month. (In fact, maybe all Parole Boards have to meet that often; I really don't know- but that's obviously the sort of review behind this quote.)
b





