Answer:
Cones are specialized photo receptors which are located inside the Retina of an eye in and around the structure called Fovea. That is option number 1 in the asked question.
Explanation:
Photo receptors are special Neuro epithelial cells that are found in the retina of an eye. They are used for Visual Phototransduction which is a process that converts light into electrical signal in the photo receptors of the eye. There are currently 3 types of photo receptors:
but important ones are rods and cones.
Rods are extremely sensitive to the light and can be triggered by just a single photon, in a very low light levels. Where as, cones require significantly brighter light i.e it requires large amount of photons to produce a signal.
At the center of Retina which is an area directly behind the lens lies a structure called Fovea or specifically Fovea Centralis. Fovea contains only cones and due to this reason it is capable of producing the vision of highest resolution or specifically highest visual acuity. Rods and cones are intermingled across the rest of Retina.
There are no photo receptors at the blind spot that is an area where ganglion cell fiber are collected into optic nerve and leaves eye.
( picture source : google)
