This code is executed using Python Tutor:

def add$\_$one $(x)$ :

$x=x+1$

return $x$

$x=0$

$y=ad{d}_{o}ne(3)$

How many variables named $x$ and $y$ appear in the memory model just before the return statement is executed?

$2$: one $x$ and one $y$

$2$: two $x\text{'}$s

$3$: two $x\text{'}$s and one $y.$

$1$: one $x$