单项选择题图4的轴侧图是下面哪一个？

单项选择题SW Co has a barrel of chemicals in its warehouse that it purchased for a project a while ago at a cost of 400 for a professional disposal company to collect the barrel and dispose of it safely. However, the chemicals could be used in a potential project which is currently being assessed. What is the relevant cost of using the chemicals in a new project proposal?