A local bank branch employs two tellers: Quick Richard can help a customer in exactly 4 minutes, while it takes Slow Paul Oke exactly 12 minutes. On average, 10 priority customers and 3 normal customers arrive at this bank per hour (in a random fashion). If we are only concerned about the waiting time of the priority customers, then what should we do?

A) Let Quick Richard help priority customers and Slow Paul Oke the normal customers.

B) It doesn’t matter which of the other options we go for.

C) Let Quick Richard help normal customers and Slow Paul Oke the priority customers.

D) Create one queue and let Quick Richard and Slow Paul Oke assist all customers in first come-first served fashion (no priority).