Identify the correct statements regarding enzymes

Options

1. AEnzymes are specific biological catalysts that can normally function at very high temperature $(T \sim 1000 \mathrm{~K})$
2. BEnzymes are specific biological catalysts that the posses well - defined active sites
3. CEnzymes are specific biological catalysts that can not be poisoned
4. DEnzymes are normally heterogeneous catalysts that are very specific in their action