Answer: Option (d) is the correct answer.
Explanation:
It is known that in solids, atoms are held closer to each other due to strong intermolecular forces of attraction between them. Due to this reason solids have fixed shape and volume.
In liquids, atoms are less tightly held due to which the atoms can easily slide past each other. Therefore, liquids occupy the space and shape of container in which they are kept.
Whereas in gases, molecules are held by weak Vander waal forces due to which they move freely and hence, occupy the volume of container in which they are kept.
Therefore, every time on changing the volume of container given sample A occupies the volume of container.
Hence, we can conclude that sample A is a gas because it contracts as the containers change.
