Which unit is used to measure volume in the metric system?

The unit used to measure volume in the metric system is liters. This metric unit is specifically designed to quantify the three-dimensional space that a substance occupies, whether it be a liquid or gas. One liter is equivalent to 1,000 cubic centimeters, and it is commonly used in various applications, from measuring beverages to scientific experiments.

In contrast, inches are a unit of length, pounds measure weight, and kilograms are used to quantify mass. These other units do not pertain to volume measurement in the metric system, confirming that liters is the appropriate choice for this context.