A company makes a product in two processes. The following data is available for the latest period,for process 1. Opening work in progress of 200 units was valued as follows. Material $2,400 Labour $1,200 Overhead $400 No losses occur in the process. Units added and costs incurred during the period: Material $6,000 (500 units) Labour $3,350 Overhead $1,490 Closing work in progress of 100 units had reached the following degrees of completion: Material 100% Labour 50% Overhead 30% The company uses the weighted average method of inventory valuation. How many equivalent units are used when calculating the cost per unit in relation to overhead?
A、500
B、600
C、630
D、700