Sheffield Corp. began the year with 8 units of marine floats at a cost of $8 each. During the year, it made the following purchases: May 5, 30 unit at $17; July 16, 16 units at $20; and December 7, 21 units at $23. Assume there are 25 units on hand at the end of the period. Sheffield uses the periodic approach.

A. Determine cost of goods sold under FIFO

B. Determine cost of goods sold under LIFO

C. Calculate the average unit cost

D. Determine the cost of goods sold under the average cost.