Answer is: D. solid.
In solid, molecules are closely packed, stiff and do not changes of shape or volume. Solid object (for example iron) does not take on the shape of its container. Glass is disordered solid, known as an amorphous solid.
Liquids have definite volume, but no fixed shape, the atomic motions are slower and the atoms are closer together.
Gases (for example nitrogen and neon) not have definite volume and fixed shape, it depends on its container.
