Question $6(1$ point$)$

Given this function definition:

def $plu{s}_{t}wo(x)$ :

return $x+2$

which of the following code fragments contain valid calls to the function? Select all correct choices.

$x=7$

$y=plu{s}_{t}wo().$

$x=3$

$x=plu{s}_{t}wo(x)$

plus$\_$two $(5)$

$a=5$

$y=$ plus$\_$two $(a)$

$y=$ plus$\_$two $($plus$\_$two $(6))$

plus$\_$two $(6,y)$