answer:
1's any cast (:: any<...any>) blocks the rest of the return values of the pcall, so it returns nil
2 has a typo (4x) so it errors on compilation
3 is valid syntax, but export is a nil global, so the not not of it is false
4 is done left to right and ends in true
∴ 4
[19] Luau // Syntax
Which one compiles and returns true?
1) return select(2, pcall(function() return true end) :: any<...any>)
2) return (function(x) return math.e^x >= x^2 + 4x + 4)(math.tau)
3) return not select(2, not const, not export)
4) return 2 < 2 == false == 2 == false