What property makes aluminium a popular choice in construction and manufacturing?

Aluminium's popularity in construction and manufacturing primarily arises from its corrosion resistance and lightweight properties. When exposed to moisture and air, aluminium forms a thin layer of aluminium oxide on its surface, which protects it from further oxidation and environmental degradation. This characteristic is particularly advantageous in outdoor applications where materials are subjected to various weather conditions.

Furthermore, aluminium's lightweight nature means that it is much easier to work with and transport compared to heavier metals like steel or iron without compromising structural integrity. This combination of being both lightweight and resistant to corrosion allows for reduced transportation costs, easier handling during construction, and a longer lifespan for the materials used, making it an optimal choice across various industries.

In contrast, the other options do not reflect the strengths of aluminium. Its magnetic properties are negligible, it is not considered heavy or dense relative to many alternatives, and it indeed has a relatively high tensile strength, negating the claim about low tensile strength. These factors collectively reinforce why aluminium is favored in construction and manufacturing contexts.