Notify the authorities, leave the location, suggest another activity.
If you sense that a friend is showing signs, id suggest asking the friend small questions, not BIG OBVIOUS ONES, that will eventually lead up to your answer, OR you could do some investigating and talk to some of the friends close ones, asking them if they know anything. hope this helps! if you'd like i could help you further
The answer to this is letter B
To be diagnosed with depression, the symptoms must be present for at least 2 weeks.
I hope this helps >~<