What is one way to determine if a tire is worn?

Answer: C — Using a tread depth gauge

Using a tread depth gauge is a reliable and effective method to determine if a tire is worn. Tires have specific tread depths designed to provide optimal grip and handling under various conditions. Over time and with use, the tread wears down, which can significantly impact safety, traction, and performance. The tread depth gauge allows you to accurately measure the remaining depth of the tire tread. Most manufacturers specify a minimum tread depth for safe operation. If the tread depth is below this minimum requirement, it is an indication that the tire is worn and may need to be replaced. This method provides a clear and quantifiable assessment of tire condition, making it a fundamental practice in motorcycle maintenance. Other options, while they may indicate different aspects of tire condition, do not directly measure tread wear. Checking for cracks in the rubber might indicate potential failure points, but does not assess the tread depth itself. Measuring air pressure is critical for tire performance and safety but does not relate to tread wear. Inspecting the color of the tire can reflect age or exposure to elements but does not provide information on tread wear and its implications for safety and handling.