Yong produces silk and polyester fabrics. Management has compiled the following unit selling price and unit cost information for the fabrics:

Yong uses the same weaving machine to make both types of fabric. It takes 0.5 hours to make 1 yard of polyester fabric and 0.75 hours to make 1 yard of silk fabric. The machine can be operated a total of 5,000 hours per year. What is the contribution margin per machine hour for silk?

• A :

  $13.58
• B :

  $9.05
• C :

  $6.70
• D :

  $4.26