Question

Plants and animals including humans cannot synthesize Vitamin B₁₂, only certain bacteria can

      make Vitamin B_12. When animals are eating, they consume these bacteria which inhabit their small intestine and    

      are considered  “good” bacteria or microbiota. As a result

1. the highest natural source of Vitamin B₁₂ for humans is eggs, milk, cheese and meats.
2. it is best to limit how much red meat we eat.
3. a vegan will not be at risk of being deficient or low in Vitamin B₁₂.
4. as long as a vegan drinks a lot of green tea which has cobalt, they should have enough Vitamin B₁₂ to avoid a deficiency.

Answer 1

Plants and animals including humans cannot synthesize Vitamin B12, only certain bacteria can make Vitamin B12. When animals are eating, they consume these bacteria which inhabit their small intestine and   are considered  “good” bacteria or microbiota. As a result,Animal foods, including meat, milk, and eggs, contain B12 and are essentially the exclusive source of the vitamin in the American food supply (not counting supplements or fortification). ... Some varieties of mushrooms and some foods made with certain fermentation processes have very small amounts of active B12.SO,OPTION A IS CORRECT.