Which of the following equations is used to calculate the break$-$even units?

a$.$ Break$-$Even Units $=$ Total Fixed Cost $/($Price $$ Variable Cost per Unit$)$

b$.$ Break$-$Even Units $=$ Total Fixed Cost $/$ Price per Unit

c$.$ Break$-$Even Units $=$ Total Variable Cost $/($Price $$ Fixed Cost per Unit$)$

d$.$ Break$-$Even Units $=$ Total Fixed Cost $/$ Variable Cost per Unit