Which component of a heterogeneous suspension forms a sediment at the bottom when left undisturbed?

The correct option is precipitate.

A heterogeneous suspension is a mixture containing insoluble solid particles distributed throughout a liquid medium. Because these solid particles are suspended rather than fully dissolved, gravity acts on them when the mixture is left undisturbed. Over time, these heavier particles settle down to the bottom of the container in a process called sedimentation.

The insoluble solid component that separates from the liquid and forms a sediment at the bottom is known as the precipitate. Let us evaluate why the other options are incorrect:
- Solute: The substance dissolved in a homogeneous solution (e.g., salt in water), which does not settle out upon standing.
- Solvent: The dissolving liquid medium in a solution (e.g., water).
- Catalyst: A substance used to increase the rate of a chemical reaction without being consumed in the process.

Thus, the component of a heterogeneous suspension that settles to form a sediment at the bottom is the precipitate.