On occasion, the FIFO and the weighted-average methods of process costing will result in the same dollar amount of costs being transferred to the next department. Which of the following scenarios would have that result:

a. when the beginning and ending inventories are equal in terms of unit numbers

b. when the beginning and ending inventories are equal in terms of the percentage of completion for both direct materials, and conversion costs

c. when there is no ending inventory

d. when there is no beginning inventory