Following is the information of Piper Company for the month of May. Units 4,200 Work in process, May 1 (10% complete) Started in May Work in process, May 31 (20% complete) Materials and conversion are incurred uniformly throughout the process. 17,850 3,150 The equivalent units of production for conversion using the weighted average method would be O a. 21,575. O b.18,900. O c. 19,467 O d. 22,000