The retinal blood vessels enter the eye at

In the mammalian eye, the 'fovea' is the center of the visual field, where

In humans,corneal transplants are rarely rejected. This is because:

The friction between the eyelids and the cornea is avoided by the secretion of

The central opening of the iris is called:

Given below are the two statements regarding photoreceptor cells of the human eye.
Statement $I$: The three types of cone cells have their own characteristic photopigments that respond to red,green,and blue lights.
Statement $II$: Sensation of white light is produced due to simultaneous equal stimulation of all three types of cone cells.
In the light of the above statements,choose the correct answer from the options given below: