Which of the following describes an extensive physical property?

An extensive physical property is one that depends on the amount of material present in a system. This means that as you increase the quantity of the substance, the extensive property will also increase accordingly. Common examples of extensive properties include mass, volume, and energy. If you double the amount of a substance, you will also double these properties.

The other options do not accurately define extensive properties. For instance, extensive properties are not independent of the amount of material; rather, they are intrinsically linked to the quantity present. The ease of observation does not define whether a property is extensive or intensive, and while extensive properties can influence chemical behavior, that is not a defining characteristic. Therefore, the correct choice highlights that extensive properties increase as the quantity of the associated material increases.