I think it is D I'm not positive
<h2>Answer </h2>
Matter
<u>Explanation </u>
A matter has distinct properties and composition that never vary. The matter is anything which possesses mass and occupies space. The matter has different characteristics and a distribution that does not change from unit to unit. Materials which cannot be disintegrated into simpler materials. Each is made of only one kind of atom in subatomic level. For example, a chair, table, and similar everything that has mass and occupies space is matter.
In gas the speed of sound is 343.2 meters per second, in liquid the speed of sound is 1,484 meters per second and in solids like steel it travels 5,120 meters per second.
