Which of the following represents the Towers of Hanoi?

A. Function Numeric unKnown(Numeric num)
   // Call function recursively until reaching 0 or 1
   If num == 0 Or num == 1 Then
      Return num
   Else
      Return unKnown(num - 2) + unKnown(num - 1)
   End If
End Function
B. Function Numeric unKnown(Numeric num)
   // Base case returns 1
   If (num == 1) Then
      Return 1
   Else
      Return (num * num) + unKnown(num - 1)
   End If
End Function
C. Function Numeric unKnown(Numeric num)
   // Declare variables
   Declare Numeric fact = 1
   Declare Numeric index // loop index
  
   // Loop
   For index = num to 1 Step -1
      fact = fact * index
  End For
   Return fact
End Function
D. Module unKnown(Integer n, sourcePeg, targetPeg, sparePeg)
   If (n > 0) Then
      moveDiscs(n - 1, sourcePeg, sparePeg, targetPeg)
   // Move disc from sourcePeg to targetPeg
      moveDiscs(n - 1, sparePeg, targetPeg, sourcePeg)
   End If
End Module

Answer: D