Consider a bank that has five tellers. The arrival rate of customers, ra$,$ is $6$ people per minute. The effective processing rate of each teller, re$,$ is $80$ people per hour. The utilization, u$,$ is:

Group of answer choices

$0\mathrm{.}075$

$0\mathrm{.}015$

$1\mathrm{.}2$

$0\mathrm{.}90$