New oil reserves have been discovered in country a. this will have the following effect.

When new oil reserves has been discovered in a country, the tendency is that the overall economy has flourished. This shifts the SRAS and LRAS curves to the right. Now the GDP potential of the economy has increased, so at full employment it can release even more output. The economy experiences economic growth.

South wales composes a lot of coal in that region.

Granite is a hard stone and lasts for a long time in both modern and ancient buildings. as proof of its durability, granite is often used in gravestones and memorials, intended to last for many years.