Which two muscles form the iris? HELP!!!?

Question

Circular, radial, suspensory, ciliary are the four choices

Answer 1

ciliary
circular

Answer 2

In anatomy, the iris (plural irises or irides) is the most visible part of the eye of vertebrates, including humans. The following describes the iris of vertebrates, not the independently evolved iris found in some cephalopods. The word comes from Greek mythology, in which Iris is the anthropromorphized form of the rainbow.

The iris consists of pigmented fibrovascular tissue known as a stroma. The stroma connects a sphincter muscle (sphincter pupillae), which contracts the pupil, and a set of dilator muscles (dilator pupillae) which open it. The back surface is covered by an epithelial layer two cells thick (the iris pigment epithelium), but the front surface has no epithelium. The outer edge of the iris, known as the root, is attached to the sclera and the anterior ciliary body. The iris and ciliary body together are known as the anterior uvea. Just in front of the root of the iris is the region through which the aqueous humour constantly drains out of the eye, with the result that diseases of the iris often have important effects on intraocular pressure, and indirectly on vision.
General structure
The iris is divided into two major regions:

The pupillary zone is the inner region whose edge forms the boundary of the pupil.
The ciliary zone is the rest of the iris that extends to its origin at the ciliary body.
The collarette is the region of the iris separating the pupillary portion from the ciliary portion. It is typically defined as the region where the sphincter muscle and dilator muscle overlap.


[edit] Histological features
From anterior (front) to posterior (back), the layers of the iris are:

Anterior border layer
Stroma
Sphincter muscle
Dilator muscle
Anterior pigment myoepithelium
Posterior pigment epithelium

[edit] Anterior surface features
The Crypts of Fuchs are a series of openings located on either side of the collarette that allow the stroma and deeper iris tissues to be bathed in aqueous humor. Collagen trabeculae that surround the border of the crypts can be seen in blue irises.
The pupillary ruff is a series of small ridges at the pupillary margin formed by the continuation of the pigmented epithelium from the posterior surface.
The Circular contraction folds, also known as contraction furrows, are a series of circular bands or folds about midway between the collarette and the origin of the iris. These folds result from changes in the surface of the iris as it dilates.
Crypts at the base of the iris are additional openings that can be observed close to the outermost part of the ciliary portion of the iris.

[edit] Posterior surface features
The Radial contraction folds of Schwalbe are a series of very fine radial folds in the pupillary portion of the iris extending from the pupillary margin to the collarette. They are associated with the scalloped appearance of the pupillary ruff.
The Structural folds of Schwalbe are radial folds extending the length of the iris that are much broader and more widely-spaced.
The Circular contraction folds are a fine series of ridges that run in a circular pattern over the entire posterior surface.

Answer 3

thanks to each and everyone of you for the answers!