There are three consecutive steps in a customer service process. The first two steps are each capable of serving $25$ customers per hour while the third step can process only $20$ customers per hour. Which of the following statements regarding this system is TRUE? Show your calculations. $(5$ points$).$A$)$ The entire system is capable of processing $25$ customers per hour.B$)$ There are floating bottlenecks in the system.C$)$ If the first two steps are run at full capacity, then the third step has a waiting line.D$)$ The first and second steps are bottlenecks for the system.