How do you close or delete a thread?

Try the 'close' function in the thread drop-down on the top right :)

James Kiesel said "Try the 'close' function in the thread drop-down on the top right"
On my page there is a title e.g."How do you close or delete a thread?"
To the right of that is a drop down arrow. Selecting that arrow yields only 4 options: Email settings, Edit, Mute and Print.
So where is the "thread drop down with a close option?

I should note that you need to be the discussion author or an admin of the discussion's group to close threads.

It would be useful to be able to select multiple threads and close all selected,