Identify the correct statements regarding enzymes

• A

  Enzymes are specific biological catalysts that can normally function at very high temperature $(T \sim 1000 \mathrm{~K})$
• Correct answer
  B

  Enzymes are specific biological catalysts that the posses well - defined active sites
• C

  Enzymes are specific biological catalysts that can not be poisoned
• D

  Enzymes are normally heterogeneous catalysts that are very specific in their action

Hence, the correct answer is option: 'B'.