Question $17$

A single munutactiving pracess has five steps. Step $1$ can process a unit in $14$ minutes Step $2$ con process a unit in $12$ minutes Step $3$ uses two identical machines, each of which can prucess unt in $16$ minutes leach unit anty needs to be processed on one of the two muchinesl Savion $4$ can process a unit in $6$ minutes. Step $5$ can process a unit in $10$ mintes Which step is the bottlEneck