Purchases and Sales During a Recent Period for Lantern,Inc

Purchases and sales during a recent period for Lantern,Inc.were:
Beginning inventory was 100 units at $1 each.
-See information for Lantern,Inc.above.Given this information,what is the cost per unit available for sale during the year when using the average cost method (rounded to the nearest cent) ?

A) $2.61
B) $3.31
C) $3.10
D) $3.53