Using conditional formatting or VBA to automatically open the next drop down menu after selecting ?

Trismos 

You may place the following code on Sheet Module to see if this is what you are trying to achieve.

e.g. if you select an answer from the dropdown list in AM4, the dropdown list in AM5 will expand automatically for you to choose an answer.

Code on Sheet Module:

Private Sub Worksheet_Change(ByVal Target As Range)
Dim n As Variant

On Error Resume Next
n = Target.Validation.Type
On Error GoTo 0

If n = 3 Then
    n = 0
    On Error Resume Next
    n = Target.Offset(1, 0).Validation.Type
    On Error GoTo 0
    If n = 3 Then
        Target.Offset(1, 0).Select
        SendKeys "%{Down}"
    End If
    NUM_On
End If
End Sub

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
NUM_On
End Sub

Code on a Standard Module like Module1:

Private Declare Sub keybd_event Lib "user32" ( _
ByVal bVk As Byte, _
ByVal bScan As Byte, _
ByVal dwFlags As Long, _
ByVal dwExtraInfo As Long)
Private Const VK_NUMLOCK = &H90
Private Const KEYEVENTF_KEYUP = &H2
Declare Function GetKeyState Lib "user32.dll" ( _
ByVal nVirtKey As Long) As Integer

Sub NUM_On()
If Not (GetKeyState(vbKeyNumlock) = 1) Then
keybd_event VK_NUMLOCK, 1, 0, 0
keybd_event VK_NUMLOCK, 1, KEYEVENTF_KEYUP, 0
End If
End Sub

SendKeys method may mess up with the Numlock. Though I have tried to handle that, it is inconsistent to work the same way. See if this is something you can work with.