The correct option is C Honorary
A post without remuneration is Option C, Honorary. Option A, Voluntary means something done or given willingly without being forced to do so or paid for the same. Option B, Sinecure is. a position that requires little or no work but status or financial benefits are given. Option D, Involuntary means not done by choice or is forced. Thus, the options A, B and D are incorrect options and the word for the given phrase is Option C, Honorary,