Recall the Application about running a software programming business to answer the following question.

If by starting your own software development business you are forced give up your job as a janitor, then the income you could have earned as a janitor is:

A$.$ not part of the opportunity cost of operating your software business.

B$.$ part of the benefit of operating your software business.

C$.$ an example of the principle of diminishing returns.

D$.$ part of the opportunity cost of operating your software business.