When the temperature of an object is raised, the increase in area is proportional to its?

The correct choice outlines a fundamental principle of thermal expansion, which states that when the temperature of an object increases, the change in area is indeed proportional to its initial area and the temperature rise. This is due to the expansive nature of materials when heated; as temperature increases, the molecules within the material move more vigorously, causing the material to expand in all dimensions.

This relationship can be described mathematically by the formula for area expansion, which involves the coefficient of area expansion, initial area, and change in temperature. The initial area serves as the baseline for measuring the change resultant from a specific increase in temperature. Essentially, the greater the initial area and the larger the increase in temperature, the more significant the increase in the total area.

While other options may seem plausible at first glance, they do not encapsulate the relationship between temperature increase and area change as directly and accurately as the correct choice does. The focus on both the initial area and the temperature rise provides a direct and clear linkage that is essential for understanding how thermal expansion works in practical applications.