Jonas Company had no beginning inventory and adds all materials at the very beginning of its only process. Assume 30,000 units were started, and 15,000 units completed. Ending work in process is 50% complete. The cost per equivalent unit of conversion is __________.

a) 

$1.00 if total conversion cost is $20,000

b) 

none of these

c) 

$1.00 if total conversion cost is $22,500

d) 

$1.00 if total conversion cost is $17,500

e) 

$1.00 if total conversion cost is $8,500