Potential customers arrive at a small bank according to a Poisson process with rate of $4$ customers per hour. The bank has only two tellers A and $B$ to serve the customers and a waiting area for four customers to queue while the two tellers are busy. The service times for the two tellers are exponentially distributed with rates $3$ customers per hour for teller A and $2$ customer per hour for teller $B.$

Assuming that the system is in steady state and that if there is only one customer is in the bank, teller A handles the customer;

$($a$)$ What type of queuing process is defined above?I mark