The unit of volume among the given options is milliliter. Volume is the amount of space occupied by an object or substance, and milliliter is a metric unit used to measure small amounts of liquid or loose substances. To identify the unit of volume, you need to understand the properties and characteristics of each option. In this case, meter is a unit of length, centimeter is also a unit of length, and milligram is a unit of weight. Therefore, the correct answer is milliliter.
