How to reference a drop down?

I have this basic spreadsheet with a single drop down. Depending on what I select in the drop down, I want to change the value of a cell.

I am having a basic lack of understanding with just finding the object qualifier for the drop down.

I tried ListBox1.value and ComboBox1.value, but I get error 424 - Object required.

Sub DropDown3_Change()

MsgBox "Hello world!"

MsgBox ListBox1.Value

End Sub

Instead of ListBox1, what should I be using to reference the drop down that is on my spreadsheet? Note that the name of my list box is DropDown3

Thanks, Bij