4. The following units of a particular item were avail¬ able for sale during the period:

Beginning inventory First purchase Second purchase Third purchase 40 units at $20 50 units at $21 50 units at $22 50 units at $23 What is the unit cost of the 35 units on hand at the end of the period as determined under the periodic inventoiy system by the fifo costing method?

A. $20 C. $22 B. $21 D.$23 AppendixLO1