Concept:Eye colour is a visible physical feature, so it is grouped under morphological variation.
Explanation:Variation means the differences that exist between individuals of the same species.
Morphological variation refers to differences in the physical appearance or structure of an organism.
Eye colour depends on the kind and amount of pigment in the iris, and it can be observed directly.
It is not a physiological variation because it does not involve a body function or internal process.
It is not an adaptive variation because eye colour is not being considered as a survival feature here.
It is not recessive because recessive describes how a trait is inherited, not the category of variation.
Thus, eye coloration is an example of an observable structural difference.
Answer:B. morphological.