Answer:
[B] Iris
Explanation:
The iris is the ring of colored tissue around the pupil which controls the size of the pupil. It adjusts the diameter of the pupil and hence determines the amount of light that is allowed to penetrate through the eye. The color of the iris depends on the amount of melanin and the pattern in which it is distributed in the eye, which is also responsible for skin and hair color.
Those who have a high level of melanin in the eyes usually have brownish or darker eyes and those who have low melanin content have blue, green or lighter eyes. The iris contains pigmentation that shapes the patterns and various colors of the eye known by every individual. Some of the structures within the eye that are not directly involved in determining eye color include the cornea, the pupil, and the retina.
Therefore, the correct answer choice is [B].