a diamond-shaped sign is a:

A diamond-shaped sign is a __________ sign.
a. regulatory
b. warning
c. guide

In traffic signs, different shapes have specific meanings that help drivers identify the type of information or message the sign conveys. Each shape is associated with a particular category of road signs, which assists in improving road safety.

Explanation:
The diamond-shaped sign is typically used for warning purposes. These signs are designed to alert drivers to potential hazards or changes in road conditions, such as sharp turns, uneven road surfaces, or pedestrian crossings.

Answer:
The correct answer is b. warning. Diamond-shaped signs are used to warn drivers about potential dangers or changes in road conditions ahead.