SSS Manufacturing has a five station work cell. Station $1$ has a production capacity of $6$ per hour. Station $2$ has a production capacity of $5$ per hour. Station $3$ has two identical machines, each of which has a production capacity of $4$ per hour $($each unit only needs to be processed on one of the two machines$).$ Station $4$ has a production capacity of $12$ per hour. Station $5$ has a production capacity of $7\mathrm{.}5$ per hour. Which station is the bottleneck station?

Station $4$

Station $3$

Station $5,$

Station $2$

Station $1$