ABC company pays a sales commission of 5% on each unit sold. If a graph is prepared with the vertical axis representing per-unit cost and the horizontal axis represented units sold how would a line that depicts sales commission be drawn?
a. As a straight diagonal line, sloping upward to the right
b. as a straight diagonal line sloping downward to the right
c. as a horizontal line
d. as a vertical line
e. as a curvilinear line