Consider a worker$-$paced line with three steps, each of which is staffed with one worker. The processing times are $3$ minutes per item for step $1,4$ minutes per item in step $2$ and $5$ minutes per item in step $3.$

If the process is operated as a pull system, at what rate does the process produce?

$-$ At the rate marked by the capacity of worker $1$

$-$ At the rate marked by the capacity of worker $2$

$-$ At the rate marked by the capacity of worker $3$