Guests are arriving at a party at a rate of $8$ per minute. Each guest will be checked in$,$ served a drink, and accompanied to his$/$her table by one receptionist, one bartender, and one usher, respectively. Both the receptionist and ushef can serve $5$ guests per minute, whereas the bartender takes $2$ minutes to serve one guest. The is a nonbottleneck resource and its utilization is

usher, $10\%$

bartender, $100\%$

usher, $100\%$

receptionist, $40\%$