The accompanying table describes the relationship between the number of workers hired by a call center each hour and the number of calls the call center can make each hour. The call center has only 1 telephone. The telephone costs the firm $5/hour (regardless of how many calls are made), and each worker is paid $10 per hour.Calls Per HourNumber of Telephones Per HourNumber of Workers Per Hour11221461616182211024112 Given the information in the table above, what is the call center's marginal cost when it goes from making 6 to 16 calls an hour?

A. $10
B. $2
C. $20
D. 50 cents

Answer: B