In the United States, there is a pattern to traffic signs so that they are easy for drivers to interpret. Which is the BEST example of this pattern?

A:Stop signs are always the same shape and size.
B:All signs indicating a hazard are yellow triangles.
C:Cities can choose what color they want for street signs.
D:Residents take drivers tests to prove that they can interpret street signs.

A: Stop signs are always the same shape and size.