What type of costs includes salaries, materials, and other expenses related to the project work?

The correct answer is that the type of costs that includes salaries, materials, and other expenses directly related to the project work is classified as direct costs.

Direct costs are specifically associated with the production of goods or services, meaning they can be traced directly to a particular project or activity. For instance, if a project requires specific materials or labor, the expenses for these elements are considered direct costs, as they are directly linked to the project's completion.

In contrast, indirect costs are expenses that cannot be traced directly to a specific project. These might include utilities, administrative salaries, or office supplies that support multiple projects. Overhead costs, which can also be seen as a subset of indirect costs, refer to ongoing expenses that are necessary to run a business but do not directly tie to a specific project. Similarly, administrative costs encompass expenses related to general administration and management. Therefore, they do not reflect costs that can be attributed solely to project work, which is why they do not fit the definition of the costs being discussed in this context.