A simple assembly line has tasks $A(2),B(4),C(3),$ and $D(3)$ that need to

be done in this order to produce a unit of product. The numbers in

parentheses are task times in minutes. Every unit goes through all $4$

steps in the same order. As a result of process improvement, the task

time for $D$ is reduced to $2$ minutes.

As a result the capacity of the process in an $8-$hour day, has increased

by:

$120$ units

$40$ units

$0$ units

$10$ units