What inventory method is better used to calculate costs of good sold?

Purchased Units Unit Cost Total Cost November 100 $8.00 $800 December 50 $10.00 $500 January 40 $12.00 $480 February 40 $11.00 $440 Units Available for Sale 230 $2,220 Ending Inventory Units Sold in March 200 Units on Hand 30 Cost of Goods Sold: What inventory method is being used to calculate costs of good sold? Specific ID Weighted average FIFO