Concept:Eye color is determined by genetic factors passed from parents to offspring.
Explanation:Heredity refers to the transmission of traits from parents to children through genes.
The color of the eye, hair, and skin is controlled by the genetic constitution inherited at conception.
For example, if both parents have brown eyes, the child is most likely to have brown eyes.
Environment, hormones, and society do not directly affect the pigment of the iris.
Hence, heredity is the main factor that decides eye colour.
Answer:B. Heredity