A post office has a single line for customers waiting for the next available postal clerk. There are two postal clerks who work at the same rate. The arrival rate of customers follows a Poisson process, while the service time follows an exponential distribution. The average arrival rate is 25 per hour and the average service rate is 14 per hour for each of the two clerks. How long does the average person spend waiting for a clerk? Select one:

a. 34.41363 minutes

b. 22.97582 minutes

c. 39.81528 minutes

d. 18.70653 minutes

e. 19.09922 minutes

f. 16.84636 minutes