In reality , it was sand . Sand used to make the finest glass . After the war , the Barcid king had ordered that no glass was to be given to outsiders at any cost . Thus , over the years , glass had become scarce and the process of glass making lost to the world .

Question: What may be the reason glass has become scarce and the process of making glass making be lost to the world ?
Answer: The King wanted to be paid before giving away glass .The King would decide who would get glass .The Barcid King did n't want the glass from his sand to go to outsiders .None of the above choices .