The receiving department employs one worker, who spends 75 percent of his time on the receiving activity and 25 percent of his time on inspecting products. His salary is $40,000. The amount of cost assigned to the receiving activity is
  a.  $34,000.
  b.  $40,000.
  c.  $10,000.
  d.  $30,000.
  e.  none of the above.