This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cofactor and prosthetic groups, Subject name: Biochemistry
Carboxylases require: 
Select and explain. 
A. Vitamin B7, B. Vitamin B2, C. Vitamin B12, D. Vitamin B1
A: Vitamin B7
Answer: A: Vitamin B7 
Explanation: All carboxylases require Vitamin B7 i.e. Biotin. Biotin is a cofactor responsible for CO2 transfer for several carboxylase enzymes. WITH REGARD TO OTHER OPTIONS: Main biochemical role of- Vitamin B2: Oxidation-Reduction reactions, required for Glutathione Reductase Vitamin B12: Synthesis of Methionine, isomerization of Methyl Malonyl CoA to Succinyl CoA by Mutase Vitamin B1: Oxidative decarboxylation, for Transketolase of HMP.