The correct answer is a) Granite. Granite is a hard, igneous rock that is often used as a building stone. It is strong and durable, and it can be polished to a high shine. Granite is also available in a variety of colors, including white, gray, pink, and red.
Shale is a sedimentary rock that is formed from the compacted remains of mud and clay. It is not as strong as granite, and it is more likely to crumble. Shale is also not as durable as granite, and it is more likely to be damaged by weathering.
Sandstone is a sedimentary rock that is formed from the compacted remains of sand. It is stronger than shale, but it is not as strong as granite. Sandstone is also more likely to be damaged by weathering than granite.
Gypsum is a sedimentary rock that is formed from the mineral gypsum. It is not as strong as any of the other rocks listed, and it is more likely to be damaged by weathering. Gypsum is also not as durable as any of the other rocks listed.
In conclusion, granite is the best choice for a building stone because it is strong, durable, and available in a variety of colors.