Radhey Shyam does unpaid work for the charity school.

Answer: Option B

Honourable : bringing or deserving honour.
Honorary : (of an office or its holder) unpaid.
Honest : free of deceit; truthful and sincere.
Honorific : given as a mark of respect but having few or no duties.
Unpaid : (of a person) not receiving payment for work done.

Synonym of Unpaid is Honorary