Which protocols does ELB use to support the load balancing of applications?

You have just set up your first Elastic Load Balancer (ELB) but it does not seem to be configured properly. You discover that before you start using ELB, you have to configure the listeners for your load balancer.

Which protocols does ELB use to support the load balancing of applications?
A . HTTP and HTTPS
B . HTTP, HTTPS, TCP, SSL and SSH
C . HTTP, HTTPS, TCP, and SSL
D . HTTP, HTTPS, TCP, SSL and SFTP

Answer: C

Explanation:

Before you start using Elastic Load Balancing (ELB), you have to configure the listeners for your load balancer. A listener is a process that listens for connection requests. It is configured with a protocol and a port number for front-end (client to load balancer) and back-end (load balancer to back-end instance) connections.

Elastic Load Balancing supports the load balancing of applications using HTTP, HTTPS (secure HTTP), TCP, and SSL (secure TCP) protocols. The HTTPS uses the SSL protocol to establish secure connections over the HTTP layer. You can also use SSL protocol to establish secure connections over the TCP layer.

The acceptable ports for both HTTPS/SSL and HTTP/TCP connections are 25, 80, 443, 465, 587, and 1024-65535.

Reference: http://docs.aws.amazon.com/ElasticLoadBalancing/latest/DeveloperGuide/elb-listener-config.html