Why do solid have fixed shape?

a. The particles do not move

b. The particles are tightly packed

c. The particles are free flowing

d. The particles vibrate

B. Would be your answer

Any matter that is a solid has a definiteshape and a definite volume. The molecules in a solid are in fixedpositions and are close together. Although the molecules can still vibrate, they cannot move from one part of the solid to another part. As a result, a solid does not easily change its shape or its volume.