How to populate form dropdown with 2nd item of model

I'm trying to create a dropdown list that's populated from a model but
which has the 2nd item in the model as the default selection. This is

Here's the model snippet.
  PROPERTY_TYPES = [['Choose', ''],
                   ['Residential', 'Residential'],
                   ['Commercial', 'Commercial']]

Here's the form snippet
<%= :property_type, Lead::PROPERTY_TYPES, :style => 'width:
100px;' %>

Is there a way to have the form default to "Residential" but still
allow the user to select either?