What best defines an intensive property of a substance?

a property that is observable
a property that is measurable
a physical property that depends on sample size
a physical property that is independent of sample size

A physical property that is independent of sample size.

Explanation:
Both an extensive and an intensive property of a substance are measurable and observable.

An extensive property of a substance depends on the size or amount of the property that is measured. For example, the amount of fat in a tissue depends proportionally on the size of the tissue, if the fat is uniformly distributed in the tissue.

On the other hand, an intensive property does not depend on the size of the object. For example, if the temperature of a jug of water is uniform, it does not matter whether you measure the temperature of a small or large portion of water in the jug.

The answer is b. hope this !