Answer :

To determine the best unit for measuring the length of a car, we need to consider the typical dimensions of a car and the practicality of the units provided.

1. Kilometers: A kilometer is a very large unit of measurement, roughly equal to 1,000 meters. Since cars are much smaller than a kilometer, using kilometers to measure a car's length would not be practical. A car's length would be a tiny fraction of a kilometer (e.g., 0.004 kilometers), making it inconvenient for usual references.

2. Centimeters: While centimeters offer precision, they are a very small unit of measurement. A car's length spans thousands of centimeters (e.g., 400 centimeters), which can be unnecessarily detailed and cumbersome.

3. Inches: Inches are commonly used in the United States, but they are relatively small units. Describing a car's length in inches would result in a large number (e.g., around 157.5 inches), which, while precise, is not as practical or straightforward as other units.

4. Meters: Meters are a suitable and practical unit of measurement for the length of a car. They provide a balance between precision and convenience. For example, a car length of around 4 meters is a straightforward and easy-to-understand measurement.

Given the considerations of practicality and typical car dimensions, the best unit to measure the length of a car is:

- Meters

Hence, the most appropriate unit for measuring a car's length is meters. The length of a typical car is approximately 4 meters.