Alison Inc., which uses the perpetual method and moving-average costing, shows the following activity for January:

Date Description Quantity Unit cost

January 1 Beginning inventory 80 $15

January 5 Purchase 150 17

January 8 Sale 110

January 15 Purchase 55 20

January 20 Sale 80

January 25 Purchase 70 22

Alison Inc.s unit cost for the January 31 ending inventory is:

Select one:

a. $18

b. $18.50

c. $18.87

d. $19.39