Concept:Identifying the labelled parts of the human eye in the diagram.Explanation:The diagram shows different parts of the eye labelled I to IV. I is the coloured iris. II is the eyelash. III is the central opening of the eye, which appears dark. This dark opening is the pupil. The pupil allows light to enter the eye. IV is the outer white layer known as the sclera.Answer:B. Pupil.
