A company which uses marginal costing has a profit of $ 37 500 for a period. Opening inventory was 100 units and closing inventory was 350 units.
  The fixed production overhead absorption rate is $ 4 per unit.
  What is the profit under absorption costing?
  A   $ 35 700
  B   $ 35 500
  C   $ 38 500
  D   $ 39 300