Which route summarization most efficiently reduces perceived network complexity that is composed of subnetworks ranging from 172.16.20.0/24 to
172.16.36.0/24?
A.
172.16.8.0/21
B.
172.16.8.0/19
C.
172.16.20.0/20
D.
172.16.0.0/18
E.
172.16.20.0/19
Why not 172.16.20.0/19?