Given below is set with four terms. In the set, a term is an odd one that cannot be grouped in the same category to which the other three belong. Identify the odd one in the set and name the category to which the remaining three belong.

Haemophilia, colour blindness, albinism, night blindness.

Night Blindness:

1. It is a symptom of an underlying disease such as a retina problem in which blindness prevents people from seeing well at night or in poor lighting.
2. Vitamin A deficiency causes this symptom in humans.

Conclusion-

a. Haemophilia, color blindness, and albinism are sex-linked disorders that are untreatable, so these are categorized together.

b. Night blindness is caused due to deficiency of Vitamin-A or nearsightedness, and it is treatable.