Identify the correct organ along with its functional characteristics. 

• The choroid is the external layer of the eye. This layer is also responsible for the formation of the ciliary body present in the eye.
• The choroid layer forms a ciliary body at the anterior part of the eye and at the posterior part it tends to dissolve into the retina.
• This layer is highly vascularized and is also responsible for providing oxygen and nutrients to the eyes. 

Hence, the correct option is A.