How Did Taylor's "Optimum Shovel" Immediately Increase the Productivity at an Eastern

How did Taylor's "optimum shovel" immediately increase the productivity at an eastern steel mill?

A) The shovel design allowed maximum work without the need for frequent rest periods.
B) The shovel reduced the motions involved from eighteen to five.
C) The shovel was discarded to create new machinery that automatized operations and reduced human work.
D) The use of a single shovel for shoveling coal into the large smelters and loading cinders into waste containers ensured an increase in productivity.