Assertion: Quasi-crystals form when certain molten alloys cool very slowly.
Reason: quasi-crystals have shorts-range as well as long-range order in their arrangement.
A. If both assertion and reason are true and the reason is the correct explanantion of the assertion
B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
C. If assertion is true but reason is false.
D. If the assertion and reason both are false.