In which order picking method, the order pickers are arranged from slowest to the fastest, the system becomes self-organ

[answerhappygod]

In which order picking method, the order pickers are arranged
from slowest to the fastest, the system becomes self-organized and
no management is required?
Select one:
a.
Bucket Brigade
b.
Pick and Pass
c.
Walk and Pick
d.
All of above
Clear my choice