The mode of transport that conveys goods at low cost per unit is

Rail transport is the mode of transport that conveys goods at a low cost per unit. This is because railways can carry a large quantity of goods over long distances at a relatively low cost. Rail transport is also energy-efficient compared to other modes of transport, making it an economical and environmentally-friendly option. Additionally, rail transport is reliable and can handle large volumes of goods, which makes it a preferred choice for businesses that require efficient and cost-effective transportation of goods.