Which feature distinguishes tent arches from plain arches?

• A. Tent arches have a significant up-thrust and do not have the same 'easy' flow that plain arches do.
• B. Tent arches have even flow.
• C. Tent arches have no ridges.
• D. Tent arches have two deltas.

Answer: (C)

In fingerprint patterns, the key difference between plain arches and tented arches is how the ridges rise at the center. A plain arch shows a smooth, gentle rise with ridges flowing evenly from one side to the other. A tented arch, by contrast, has a sharp central up-thrust—a tent-like peak formed by a more abrupt, angular rise in the central ridges. This central spike is what makes the pattern look like a tent.

So the best description is the presence of a central, tent-like ridge peak. The idea that tented arches have even flow describes plain arches, and saying there are no ridges misstates both patterns. Deltas aren’t a feature of arches at all, since deltas are associated with loops and whorls.