This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vitamins, Subject name: Social & Preventive Medicine
Richest source of Vitamin-A - 
Select and explain. 
A. Halibut liver oil, B. Carrot, C. Butter, D. Margarine
A: Halibut liver oil
Answer: A: Halibut liver oil 
Explanation: Ans. is 'a' i.e., Halibut liver oil Retinol content of selected foodsRetinol equivalents (RE)(mcg/100 g)Halibut liver oil900,000Carrot1167Cod liver oil18,000Spinach607Liver, Ox16,500Amaranth515Butter825Green leaves300Margarine900Mango, ripe313Cheese650Papaya118Egg140Orange25Milk, Cow38Tomato84Fish40