A non-proteinaceous enzyme is
(a) lysozyme (b) ribozyme
(c) ligase (d) deoxyribonuclease
(b) Ribozyme is a form of ribosomal RNA (23 SrRNA) which acts as a catalyst in splicing of RNA during protein synthesis. It is the only non-protein enzyme known so far, rest all the enzymes are proteinaceous. Hence, option (b) is correct.