This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lipoproteins, Subject name: Biochemistry
Which is the most essential fatty acid? 
Select and explain. 
A. Linolenic acid, B. Linoleic acid, C. Arachidonic acid, D. Oleic acid
B: Linoleic acid
Answer: B: Linoleic acid 
Explanation: Most essential fatty acid is Linoleic acid (18-C, 2 double bonds). Linoleic acid Precursor of omega-6. Synthesize : Gamma Linolenic acid Arachidonic acid. Polyunsaturated fatty acids / Essential Fatty Acids (EFA) Cannot be synthesized in body. Enzymes that can introduce double bonds beyond 9th carbonare absent in humans. 2 essential fatty acids in diet - Linoleic and a-Linolenic acid. Most Essential Fatty Acid- Linoleic acid (because it can synthesize Arachidonic acid).