The Cyclops and Dragon both have a lot of friends that are serving as bridesmaids and groomsmen. Also, the King is acting as the officiant of the ceremony. Poly determines that the best way to organize everyone is for the officiant to stand at a vertex at the front, and to have the bride and groom stand across from each other. The bridesmaids and groomsmen will then line up so that the entire group forms a "U" shape that is symmetric about a line that passes through the point where the officiant stands. What type of function most accurately models this structure?

quadratic
radical
linear
rational