What Will Be Displayed When the Button Is Clicked On $\operatorname { Dim } x , y$

What will be displayed when the button is clicked on? Private Sub btnDisplay_Click(...) Handles btnDisplay.Click
$\operatorname { Dim } x , y$ As String
$\mathbf { x } =$ "tin"
$\mathrm { y } =$ "can"
Swap (x, y)
txtOutput. Text $= x \& " "\&y$
End Sub
Sub Swap (ByRef $x$ As String, y As String)
Dim temp As String
temp $= \mathbf { x }$
$\mathbf { x } = \mathbf { y }$
$\mathrm { y } =$ temp
End Sub

A) tin can
B) can tin
C) tin tin
D) can can