The Following Question(s) Are Based on the Reaction a

The following question(s) are based on the reaction A + B ↔ C + D shown in the accompanying figure.
-You have isolated a previously unstudied protein, identified its complete structure in detail, and determined that it catalyzes the breakdown of a large substrate. You notice it has two binding sites. One of these is large, apparently the bonding site for the large substrate; the other is small, possibly a binding site for a regulatory molecule. What do these findings tell you about the mechanism of this protein?

A) It is probably a structural protein that is involved in cell-to-cell adhesion.
B) It is probably an enzyme that works through allosteric regulation.
C) It is probably an enzyme that works through competitive inhibition.
D) It is probably a cell membrane transport protein-like an ion channel.
E) It is probably a structural protein found in cartilage or skeletal tissue.