This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Proteins, Fats, Rich Sources, Subject name: Social & Preventive Medicine
Limiting (deficient) amino acid in Maize is? 
Select and explain. 
A. Tryptophan, B. Leucine, C. Threonine, D. Methionine
A: Tryptophan
Answer: A: Tryptophan 
Explanation: LIMITING AMINO ACID is AA deficient in a food item Maize - Tryptophan & Lysine Wheat - Threonine & Lysine Pulse - Methionine & Cysteine Supplementary action of proteins: Two different food items must be eaten together.