Explanation:

- The word "tread" refers to stepping or walking on something.

- Option 1: Walk – Walking involves moving at a regular pace by lifting and setting down each foot in turn. This option aligns with "tread" as they both involve a similar action of moving on a surface.

- Option 2: Climb – Climbing refers to ascending or moving upward using hands and feet. It doesn’t match the general action of stepping or treading.

- Option 3: Follow – Following means to come after a person or thing, which is more about directionality than the act of stepping.

- Option 4: Run – Running involves moving rapidly, which is distinct from the more deliberate action of treading.