Answer:
Iris.
Step-by-step explanation:
Eye is one of the most important sense organ of the body that helps to receive the light and also helps in the maintenance of the body equilibrium. The pupils regulate the amount of the light that enters in the eyes.
The Leslie has some eye problem and doctors use a sedative in her eyes. The sedative drug has the largest effect on the iris of the eye. The iris decides the color of the eye and also regulate the proper functioning of the pupil of eye.
Thus, the correct answer is iris.