The correct answer is: D. A refinery product
Plastic asphalt is a refinery product that is made from crude oil. It is a black, sticky substance that is used in a variety of applications, including road construction, roofing, and waterproofing.
Option A is incorrect because plastic asphalt is not used as a water proofing layer over roof. This is typically done with a different material, such as roofing felt or membrane.
Option B is incorrect because plastic asphalt is not a mixture of cement and asphalt. Cement is a powder that is used to make concrete, while asphalt is a sticky substance that is used in road construction.
Option C
is incorrect because plastic asphalt is not a natural asphalt. Natural asphalt is a substance that is found in the earth, while plastic asphalt is a man-made product.