Answer: Option (C) is the correct answer.
Step-by-step explanation:
A property that changes chemical composition of a substance is known as chemical property.
For example, precipitation, reactivity, toxicity etc are chemical property.
A chemical property or reaction will always lead to the formation of a new product.
So, chemical properties such as combustibility, are generally observed as the identity of a substance changes and one or more new substances form.
On the other hand, a property that does not bring any change in chemical composition of a substance are known as physical properties.
For example, shape, size, mass, volume, density, etc of a substance are all physical properties.
Thus, we can conclude that the statement chemical properties, such as combustibility, are generally observed as the identity of a substance changes and one or more new substances form, best describes chemical properties of matter.