The prisoner has been languishing in the jail forn the last many years.

Answer: Option C

Enjoying : take delight or pleasure in (an activity or occasion).
Avoiding : keep away from or stop oneself from doing (something).
Suffering : become or appear worse in quality.
Convicted : having been declared guilty of a criminal offence by the verdict of a jury or the decision of a judge.
Languishing : failing to make progress or be successful.

Synonym of Languishing is Suffering