The correct answer is (b) beri-beri.
Beri-beri is a disease caused by a deficiency of thiamine (vitamin B1). It is characterized by weakness, fatigue, nerve damage, and heart problems. It is most common in countries where polished rice is the main cereal in the diet, as polished rice is low in thiamine.
Pellagra is a disease caused by a deficiency of niacin (vitamin B3). It is characterized by skin lesions, diarrhea, and mental problems. It is most common in countries where corn is the main cereal in the diet, as corn is low in niacin.
Scurvy is a disease caused by a deficiency of vitamin C. It is characterized by bleeding gums, loose teeth, and skin problems. It is most common in people who do not eat enough fruits or vegetables.
Osteomalacia is a disease caused by a deficiency of vitamin D. It is characterized by soft bones and bone pain. It is most common in people who do not get enough sunlight or who do not eat enough dairy products.