This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Abzyme is an 
Select and explain. 
A. Isoenzyme, B. Allosteric enzyme, C. Abnormal enzyme, D. Antibody with a catalytic activity
D: Antibody with a catalytic activity
Answer: D: Antibody with a catalytic activity 
Explanation: It has also become possible to produce hybrid enzymes by rearrangement of genes. Another innovative approach is the production of abzymes or catalytic antibodies, the antibody enzymes​.