The correct answer is: A. Ship building.
Contract cost is the total cost of a contract, including the cost of materials, labor, and overhead. It is used in a variety of industries, including ship building.
In ship building, contract cost is used to determine the total cost of a ship. This information is then used to set the price of the ship and to track the progress of the construction.
Contract cost is also used to determine the profitability of a ship building project. By comparing the contract cost to the actual cost of the project, ship builders can determine whether they are making a profit or a loss.
The contract cost is calculated by adding the cost of materials, labor, and overhead. The cost of materials includes the cost of the raw materials used to build the ship, such as steel and wood. The cost of labor includes the cost of the workers who build the ship, such as welders, carpenters, and electricians. The cost of overhead includes the cost of things like rent, utilities, and insurance.
The contract cost is a critical piece of information for ship builders. It is used to determine the price of the ship, to track the progress of the construction, and to determine the profitability of the project.
The other options are incorrect because they are not industries in which contract cost is used.