What unit is larger than a milliliter?

A liter is the correct choice because it is a metric unit of volume that is equal to 1,000 milliliters. This means that one liter is significantly larger than a milliliter, as it represents a quantity that is one thousand times greater. In the metric system, units often scale by factors of ten, and in this case, the relationship clearly indicates that liters serve as a larger volume measurement when compared to milliliters.

The other units mentioned—microgram, milligram, and gram—are all units of mass, not volume, and they are smaller or equivalent in quantity when referring to mass than their corresponding milliliter counterpart in terms of volume. Therefore, comparing them to a milliliter does not apply in the context of measuring volume.