Rachel Left Her Job as a Graphic Artist, Where She

Rachel left her job as a graphic artist, where she earned $42,000 per year, to open her own graphic arts firm. Her implicit costs of the new business include:

A) only the expenses incurred for office space, equipment, and supplies.
B) only her forgone salary of $42,000 per year.
C) both the expenses incurred for office space, equipment, and supplies and her forgone salary of $42,000 per year.
D) neither the expenses incurred for office space, equipment, and supplies nor her forgone salary of $42,000 per year.