(20 points) MetalCo uses turning machines to convert steel bars into various precision parts. Once the machines are set up, a typical batch runs for about two hours and produces 1,000 parts. However, some batches are much larger and can run all day. After every batch all parts produced are transported into a warehouse using large containers that can handle up to 3,000 parts. The cost of transportation is $20 for every trip a container makes from the turning machine area to the warehouse. Which of the following is true about the transportation costs?

Group of answer choices

Transportation costs vary both at the unit level and at the batch level.

Transportation is a unit-level cost.

Transportation is a batch-level cost.

Transportation is a facility-level cost.

None of these.