Solution:Beri-beri disease is caused by a deficiency of Vitamin B₁ whose chemical name is Thiamin. Other options are correctly matched. Riboflavin is the chemical name of Vitamin B₂, which is responsible for stomatitis, cheilosis and malnutrition.
Deficiency of Vitamin D (Calciferol) leads to osteomalacia in adults and rickets in children, both of which are characterized by soft bones.
Deficiency of niacin causes pellagra, characterized by dermatitis, diarrhea, and dementia.
Deficiency of vitamin B12 (Cobalamin) causes pernicious anemia, an autoimmune condition that impairs the absorption of B12, leading to anemia.