Explanation:

- Osmium (Option 1): The densest stable element known on Earth. Its density is approximately 22.59 g/cm³. It is a hard, bluish-white metal in the platinum group.

- Rhodium (Option 2): Part of the platinum group, it's used in catalytic converters and jewelry, but it's not as dense as osmium.

- Aluminium (Option 3): A lightweight metal commonly used in industries like automotive and aerospace. It has a much lower density compared to osmium.

- Tungsten (Option 4): Known for its high melting point and is used in lightbulb filaments, but still less dense than osmium.