The first step in fatty acid synthesis involves: (A) Acetyl CoA carboxylase, (B) b-Hydroxyl CoA dehydrogenase, (C) Acetyl dehydrogenase, (D) Pyruvate kinase
Answer is A. Acetyl CoA carboxylase 

Production of malonyl-CoA from acetyl-CoA is the initial and rate limiting step in fatty acid synthesis. The reaction is catalyzed by acetyl-CoA carboxylase.