You cannot embolden only the word BOLD in a dropdown form field, unless you convert the field result to plain text (whereupon it will no longer be a form field). You can however embolden the whole field range if the dropdown result contains the world BOLD e.g.
Code:
Public Sub Test1()
Dim bProtected As Boolean
Dim oFld As FormField
If ActiveDocument.ProtectionType <> wdNoProtection Then
bProtected = True
ActiveDocument.Unprotect Password:=""
End If
With ActiveDocument.Content.Find
.Text = "BOLD"
.MatchWildcards = True
.MatchCase = True
.Replacement.Font.Bold = True
.Execute Replace:=wdReplaceAll
End With
For Each oFld In ActiveDocument.FormFields
If InStr(1, oFld.Result, "BOLD") > 0 Then
oFld.Range.Font.Bold = True
Else
oFld.Range.Font.Bold = False
End If
Next oFld
If bProtected = True Then
ActiveDocument.Protect _
Type:=wdAllowOnlyFormFields, _
NoReset:=True, _
Password:=""
End If
End Sub