Your question 3 is wrong. Why?
1) You don't output anything.
2) You have no return, so if by "output" you meant return, it's null.
Though I assume by "output" you mean the value of A, which with no VAR/LET/CONST attempts to access the global.
And a lot of these show quite well why I think LET and CONST are dumbass trash that just make things even more complex and hard to maintain.
Just as how most of the time assigning functions to variables is a bit dumbass, as are those derpy painfully cryptic arrow functions where I swear the ECMA won't be happy until JS looks like brainf***.