Explanation:

- To find how much air can be held in a cubical box, calculate the volume of the cube.

- The formula for the volume of a cube is \( \text{Volume} = \text{side}^3 \).

- In this case, the side length of the cube is 12 metres.

- So, the volume is \( 12 \times 12 \times 12 = 1728 \) cubic metres.

- Option 1: 1872 cubic metres – Incorrect, as it doesn't match the calculated volume.

- Option 2: 1728 cubic metres – Correct. This is the correct volume of the cube.

- Option 3: 1278 cubic metres – Incorrect. This doesn't match the calculated volume.

- Option 4: 1827 cubic metres – Incorrect. This also doesn't match the calculated volume.