Which of the following HTTP headers is a CORS header?

Which of the following HTTP headers is a CORS header?

Which of the following commands lists the nodes in a Docker Swam cluster?

What statement is true regarding the Swarm service created by the following command?
docker service create -name myweb -network webnet -mode global nginx

CORRECT TEXT
Which docker-machine sub command outputs a list of commands that set environment variables which are required to make docker work with a Docker host managed by docker- machine? (Specify only the sub command without any path or parameters.)