Effie Company uses a periodic inventory system. Details for the inventory account for the month of January, 2015 are as follow Units Per unit price Total $1.000 200 $5.00 Balance, 1/1/15 530 5.30 100 Purchase, 1/15/15 100 5.50 550 Purchase. 1/28/15 An end of the month (1/31/15) inventory showed that 140 units were on hand. How many units did the company sell during January, 2015? O a. 140 O b. 260 c. 200 Od. 60