Final answer:
The given options that represent opportunity costs are using a current employee who is about to be laid off for a project, research and development costs for a new project, and building a new building on a vacant lot.
Step-by-step explanation:
Opportunity cost is the value of the next best alternative or the lost opportunity to do or consume something else. In the given options, the following represent opportunity costs:
- Using a current employee who is about to be laid off to run a project on a day-by-day basis. The opportunity cost is the work that the employee could have done if they were not running the project.
- The research and development costs related to a new project. The opportunity cost is the use of resources for research and development instead of allocating them to other projects.
- Building a new building on a vacant lot owned by the firm. The opportunity cost is the potential alternative uses of the vacant lot, such as selling it or using it for a different purpose.