Which route summarization most efficiently reduces perc…

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