Why isn't my profile picture public on Facebook?

[Mary]

So I'm really new to Facebook and figuring out how to use it. I have this profile picture (of a cat) and I thought profile pictures were public. I looked myself up to see how much of what was on my profile was public, and the icon for a person without a picture came up. (I want it to be visible publicly so that if a friend , who I'm not friends with on Facebook, looks me up they'll know it's me) I went to the edit and it doesn't give the option to be visible to the public, just friends or friends of friends.
What's going on?

[Hibu]

U should go at your profile n select the photo... Pick up any of the photo n go to edit n make the friends to public.Now,your every photo will be seen.

[Rìshád]

Go to your photo which you want to make as public,then scroll down,there you can see a small icon (two people in black&white colour).click on it then change it to round shaped icon(it is the symbol of public in fb).
*good luck*
Add me on fb https://facebook.com/rishad.kalikavu

[Dskyisfalling211]

if you're bellow 18,you cannot go public.
I think o nly the cover photo can be on public