In the diagram, the structure labelled I is sensitive to

In the diagram, the structure labelled I is sensitive to light and touch. Structure I represents the eye, which is the organ of sight in animals. The eye is sensitive to light and is responsible for vision. Additionally, the eye is also sensitive to touch and is protected by eyelids and eyelashes, which help to keep out foreign particles and other irritants. Therefore, the structure labelled I is sensitive to both light and touch. The other options are incorrect as they suggest that the structure is sensitive to chemicals only or light only, which is not true for the eye.