What is the subnet address for the IP address 172.19.20.23/28?

What is the subnet address for the IP address 172.19.20.23/28?

A.
172.19.20.0

B.
172.19.20.15

C.
172.19.20.16

D.
172.19.20.20

E.
172.19.20.32

Explanation: