Oops I really seem to have difficulties here. I thought with such questions you take suit data, data without step. Work out like we always do then add $15000 to TFC when working out for output 14000 units? 97500-86000/9000-7000 to get a variable cost of $5.75/u This gives us TFC of $45750 TC @ 14000 will then be: ($5.75*14000)=$40250+$45750+$15000= $141250 not part of the options anyway! If we have to reduce $141000 by $15000 to have suit data, why are we still working with 12000 units?