Which state's molecule arrangement allows it to maintain a definite volume?

The arrangement of molecules in a liquid allows it to maintain a definite volume. In liquids, the molecules are closely packed together, which enables them to be in close proximity while still allowing some movement past each other. This arrangement means that liquids resist compression and do not change volume easily, despite being able to flow and take the shape of their container.

In contrast, solids have a definite shape and volume because their molecules are rigidly fixed in a structured arrangement, while gases have widely spaced molecules that move freely and can expand to fill any container, resulting in not having a definite volume. Plasma, being a state of matter made up of charged particles, can also vary in volume depending on environmental conditions. Therefore, solids and gases cannot be considered for this question because of their differing characteristics in terms of volume maintenance.