This code is executed using Python Tutor: \[ \begin{array}{l} \text { def add_one }(x) \text { : } \\ x=x+1 \\ \text { return } x \\ x=0 \\ y= \text { add_one }(3) \\ \text { print(y) } \end{array} \] How many variables named x and y appear in the memory model just before the print(y) statement is executed? 3: twp x s and one y 2. two 's 4: one x and two y5 2: one x and one y