Explanation:

A brick is an example of a cuboid. Let's understand why.

Definition of a Cuboid:
A cuboid is a 3-dimensional solid that has six rectangular faces, eight vertices, and twelve edges. The length, breadth, and height of a cuboid are perpendicular to each other.

Properties of a Cuboid:
- It has six rectangular faces.
- All the faces are perpendicular to each other.
- The opposite faces are equal in size and shape.
- It has eight vertices (corners).
- It has twelve edges.

So, why is a brick a cuboid?

A brick is a rectangular block made of clay, sand, or other materials. It has six rectangular faces, eight vertices, and twelve edges, which satisfy the properties of a cuboid. The length, breadth, and height of a brick are perpendicular to each other, which makes it a 3-dimensional solid.

Hence, a brick is an example of a cuboid.

Conclusion:

A brick is a cuboid because it has six rectangular faces, eight vertices, and twelve edges, which are perpendicular to each other. The length, breadth, and height of a brick also satisfy the properties of a cuboid.

Option D