how to shuffle an array of 4 numbers in visual basic?

I would like to shuffle 4 numbers randomly in visual basic. These represent the 4 answers to a multiple choice question that I want to present in a different order every time. I have found the following code, but I cannot work out what the input and output variables are:

Public Sub Shuffle(Of T)(ByRef A() As T)
    Dim last As Integer = A.Length - 1
    Dim B(last) As T
    Dim done(last) As Byte
    Dim r As New Random(My.Computer.Clock.TickCount)
    Dim n As Integer
    For i As Integer = 0 To last
        Do
            n = r.Next(last + 1)
        Loop Until Not done(n)
        done(n) = 1
        B(i) = A(n)
    Next
    A = B

End Sub

Thanks for any help.