Maurice gifts had the following costs in March when 600 music boxes were produced : marerials, $3,800; labor cost, $1,200; depreciation, $1,000; rent, $900; and other fixed costs $500. If production changes to 500 units, and production still remains within relevant range, which of the following will stay the same?

A) Total cost per unit

B) Variable cost per unit

C) Fixed cost per unit

D) None of these

E) Total variable cost