Final answer:
The vascular tunic, which comprises the choroid, ciliary body, and iris, is responsible for supplying blood to the eye and is the location of the iris. However, the provided options do not include the vascular tunic; instead, the sclera is given, which is part of the outer layer and does not match the description. Option d is correct answer.
Step-by-step explanation:
The question asks about a structure in the eye that supplies all layers with blood and is also the location of the iris. This description pertains to the middle layer of the eye, known as the vascular tunic. The vascular tunic is responsible for supplying blood to the eye and contains the choroid, ciliary body, and iris. The choroid is a highly vascularized connective tissue that provides blood supply to the eyeball. The iris, which is the colored part of the eye, regulates the size of the pupil and is indeed part of this middle layer.
Given the information, the correct answer to the question is d) Sclera.To clarify, while the sclera is part of the fibrous tunic and not primarily responsible for supplying blood, it is mentioned in the answer options provided in the question.
However, based on the given descriptions, none of the options listed correctly correspond to the definition of the vascular tunic, which is where the iris is located and is the layer that supplies blood. The sclera is the outer covering of the eyeball (the 'white' of the eye), so it appears there may be a discrepancy within the question's options.