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
Which of the following is rate limiting enzyme of fatty acid synthesis 
Select and explain. 
A. Acetyl CoA carboxylase, B. Carnitine acyltransferase I, C. HMG CoA Synthase, D. HMG CoA reductase
A: Acetyl CoA carboxylase
Answer: A: Acetyl CoA carboxylase 
Explanation: Acetyl CoA Carboxylase is the rate limiting enzyme.

It is activated by Insulin, Citrate.
Inhibited by Glucagon, Palmitoyl CoA.
It converts acetyl CoA to Malonyl CoA.
Carnitine acyltransferase I is the rate limiting enzyme for fatty acid oxidation.
HMG CoA synthase is RLE for Ketone body synthesis.
HMG CoA reductase is RLE for Cholesterol synthesis.