Roc3, Inc. engaged in the following inventory transactions this period: Date Purchase Sale Beg. 50 Units @ $20 cost each 1/10 40 Units @ $35 retail each 1/15 35 Units @ $18 cost each 1/20 25 Units @ $35 retail each 1/25 20 Units @ $16 cost each Using a periodic approach, What is Roc3's January cost of goods sold using LIFO? $1,150. O $680. $1,270. O $800