The original macro does not work, because what you are actually looking for is not what you said you were looking for. The macro looks for paragraphs that start with 'Choice (', whereas now you tell us that the paragraph begins with 'Answer ('.
Code:
For Each oPara In ActiveDocument.Paragraphs
If oPara.Range.Text Like "Choice (*" Then
oPara.Style = "Extra Space"
End If
Next oPara
Then you have added in a completely different set of criteria. with phrases that are in the same paragraph, which the code was never intended to address.