There are no units in process at the beginning of the period, 500 units in process at the end of the period that are 30% complete, and 3,000 units transferred out during the period. Based on this information, how many units were started during the period under the weighted-average method? Select one: O a. 2,500 O b. 3,500 O c. 3,150 O d. 3,000