Answer: Option (a) is the correct answer.
Explanation:
Chemical changes are defined as the change which tend to show difference in chemical composition of a substance.
For example, toxicity, reactivity, combustion, change in energy, precipitation etc are all chemical properties.
A chemical change will always lead to the formation of a new compound and this change is irreversible in nature by any physical means.
On the other hand, a change which is unable to bring any difference in chemical composition of a substance is known as a physical change.
For example, change in shape, size, mass, volume etc are all physical properties.
Thus, we can conclude that out of the given options fracture formation does NOT indicate that a chemical change may have taken place.