Emily's home computer experienced a power outage and later regained power. Kolby can no longer send messages to Emily's server. What is the most likely explanation?

• A. Emily's ISP assigned a different IP address after power restoration.
• B. Emily's DNS cache expired.
• C. Kolby's IP address changed.
• D. Packets were corrupted in transit.

Answer: (A)

After a power outage, home networks often get a new public IP from the ISP because the modem/router reboots and renews its DHCP lease. If Emily’s server is now at a different address, Kolby’s messages still go to the old IP and never reach the server. Reaching the correct server requires using the current IP (or a domain that updates to the new IP). The other ideas don’t fit as cleanly: a DNS cache expiring could cause resolution issues but wouldn’t necessarily coincide with the outage itself, and Kolby’s own IP changing or data being corrupted wouldn’t typically explain a single, clear failure to reach Emily’s server after a restart.