Question: In this code snippet, why does the compiler not allow the value of y to change?

1. `y` must be declared with `var` to be mutable
2. `y` is an implicitly immutable value
3. `y` can change only in a while loop
4. In order to change `y`, it must be declared outside of the loop

Answer: The correct answer of the above question is Option B:`y` is an implicitly immutable value