Users trying to access a website using HTTPS are being blocked by the firewall. Which of the following ports needs to be allowed?

Port 80 is the default port for unencrypted HTTP traffic, not HTTPS; allowing only port 80 would permit insecure web traffic but still block HTTPS connections.

Port 143 is the default port for IMAP (Internet Message Access Protocol), which is used to retrieve email from a mail server, not for web browsing.

HTTPS is the secure version of HTTP that encrypts traffic using TLS (Transport Layer Security). By default, HTTPS traffic is transmitted over TCP port 443. For users to successfully connect to HTTPS websites, the firewall must allow inbound and outbound traffic on TCP port 443; without this, the TLS handshake and encrypted session cannot be established.

Port 3389 is the default port for RDP (Remote Desktop Protocol), used for remote desktop connections to Windows systems, not for HTTPS web traffic.