Explanation:

- The SI unit of work is Joule.

- Option 1: Hertz – This is the unit of frequency (cycles per second), not work.

- Option 2: Pascal – This is the unit of pressure (force per unit area), not related to work.

- Option 3: Joule – This is the correct SI unit for work and also for energy.

- Option 4: Decibel – This is a unit for measuring sound intensity or loudness, not work.

- Work is done when a force causes movement; its unit, Joule, is defined as one newton-meter.