The following diagram shows a $4-$step process that begins with Operation $1$ and ends with Operation $4.$ The rates shown in each box represent the effective capacity of that operation.

The following diagram shows a $4-$step process that begins with Operation $1$ and ends with Operation $4.$ The rates shown in each box represent the effective capacity of that operation.

b$.$ Which action would yield the greatest increase in process capacity:

$1.$ increase the capacity of Operation $1$ by $10$ percent;

$2.$ increase the capacity of Operation $2$ by $10$ percent; or

$3.$ increase the capacity of Operation $3$ by $12$ percent?