Select the option that is related to the Fourth term in the same way as the first term is related to the second term.

Pinna : Ears :: ? : Eyes

Cornea

Pinna : Ears :: ? : Eyes

The logic followed here is :

Pinna : Ears = The pinna is the only visible outer layer of the ear

Similarly

? : Eyes

The Cornea in our eye's clear, protective outer layer

Hence Cornea is correct option