You are configuring static IPv4 addresses for two computers, Perth and Brisbane, on an isolated private wired subnet.

You configure Perth with the IPv4 address 172.16.10. 140 and the subnet mask 255.255.255.0.

You configure Brisbane with the IPv4 address 172.16.10. 210 and the subnet mask 255.255.255.0.

You enter ping 172.16.10.140 on Brisbane, but the command times out. Similarly, entering ping 172.16.10.210 on Perth fails to locate the Brisbane computer’s IPv4 address.

What is the likely reason for this lack of connectivity?

A.
DNS service is not available on the subnet.

B.
The computers should have different subnet masks.

C.
You have not specified a default gateway.

D.
You need to permit ICMPv4 traffic through the firewalls of both computers.