Solids have a definite shape and volume. Liquids have a definite volume, but take the shape of the container. Gases have no definite shape or volume.

Which of these has a fixed shape and volume?

Solids have a fixed shape and occupy a fixed volume. Liquids, because they flow, can occupy whatever shape their container has, so they do not have a fixed shape. Because the particles in liquids are very close together (barely further apart than in solids) liquids do not easily compress, so their volume is fixed.

What has a definite shape and volume?

A solid has a definite shape and a definite volume. The particles that make up a solid are packed very closely together.