Which Mechanism Does Ssh Use to Interact with the SSH

Multiple Choice

Which mechanism does ssh use to interact with the SSH agent?

A) Connecting to port 2222 which is used by the system-wide SSH agent.
B) Using the fixed socket .ssh-agent/ipc. Using the fixed socket .ssh-agent/ipc.
C) Creating an alias replacing ssh with calls to ssh-agent . Creating an alias replacing ssh with calls to ssh-agent .
D) Starting ssh-agent as a child process for each ssh invocation. Starting as a child process for each ssh invocation.
E) Evaluating environment variables such as SSH_AUTH_SOCK . Evaluating environment variables such as SSH_AUTH_SOCK