Correct Option: B

Vitamin B₁₂ also called cobalamin, is a watersoluble vitamin with a key role in the normal functioning of the brain and nervous system, and for the formation of blood. Vitamin B₁₂ is found in foods that come from animals, including fish and shellfish, meat (especially liver), poultry, eggs, milk, and milk products. While lacto-ovo vegetarians usually get enough B₁₂ through consuming dairy products, vegans will lack B₁₂ unless they consume B₁₂-containing dietary supplements or B₁₂-fortified foods.