ANS:C - stoneware

The most commonly used material for sewers for carrying sewage in normal situations is stoneware. Explanation: Stoneware pipes are widely used in sewer systems due to their durability, resistance to corrosion, and ability to withstand the harsh conditions of sewage transportation. They are made from clay and fired at high temperatures, resulting in a dense and hard material that is resistant to chemical corrosion and abrasion. Stoneware pipes are also relatively inexpensive compared to materials like stainless steel and have a long service life, making them a preferred choice for sewer infrastructure in many regions.