Find the odd number / letters / word from the given alternative:

Scurvy
Rickets
Night-blindness
Influenza

The odd one out is D, influenza. The other three options are all diseases caused by a deficiency of a vitamin. Scurvy is caused by a deficiency of vitamin C, rickets is caused by a deficiency of vitamin D, and night-blindness is caused by a deficiency of vitamin A. Influenza is a viral infection that is not caused by a deficiency of any vitamin.

Scurvy is a disease caused by a lack of vitamin C. It is characterized by weakness, fatigue, bleeding gums, and skin lesions. Scurvy was once a common disease among sailors, who did not have access to fresh fruits and vegetables on long voyages. Today, scurvy is rare in developed countries, but it can still occur in people who have poor diets or who are malnourished.

Rickets is a disease caused by a lack of vitamin D. It is characterized by soft bones, bowed legs, and delayed growth. Rickets was once a common disease among children, who did not get enough sunlight or who did not eat enough dairy products. Today, rickets is rare in developed countries, but it can still occur in children who have poor diets or who are malnourished.

Night-blindness is a condition that causes difficulty seeing in dim light. It is caused by a lack of vitamin A. Night-blindness was once a common problem in people who did not eat enough fruits and vegetables. Today, night-blindness is rare in developed countries, but it can still occur in people who have poor diets or who are malnourished.

Influenza is a viral infection of the respiratory tract. It is characterized by fever, cough, sore throat, and muscle aches. Influenza is a common illness, and most people recover within a week or two. However, influenza can be serious, especially for young children, the elderly, and people with chronic health conditions.