select_tag(要素名, オプションタグ=nil, オプション={}, HTML属性={} or イベント属性={})
select_tag "people", options_from_collection_for_select(@people, "id", "name")
#=> <select id="people" name="people"><option value="1">David</option></select>
select_tag "people", options_from_collection_for_select(@people, "id", "name", "1")
#=> <select id="people" name="people"><option value="1" selected="selected">David</option></select>
select_tag "people", raw("<option>David</option>")
#=> <select id="people" name="people"><option>David</option></select>
select_tag "colors", raw("<option>Red</option><option>Green</option><option>Blue</option>"), multiple: true
#=> <select id="colors" multiple="multiple" name="colors[]"><option>Red</option><option>Green</option><option>Blue</option></select>
select_tag "access", raw("<option>Read</option><option>Write</option>"), multiple: true, class: 'form_input', id: 'unique_id'
#=> <select class="form_input" id="unique_id" multiple="multiple" name="access[]"><option>Read</option><option>Write</option></select>
select_tag "people", options_from_collection_for_select(@people, "id", "name"), include_blank: true
#=> <select id="people" name="people"><option value="" label=" "></option><option value="1">David</option></select>
select_tag "people", options_from_collection_for_select(@people, "id", "name"), include_blank: "All"
#=> <select id="people" name="people"><option value="">All</option><option value="1">David</option></select>
select_tag "people", options_from_collection_for_select(@people, "id", "name"), prompt: "Select something"
#=> <select id="people" name="people"><option value="">Select something</option><option value="1">David</option></select>
select_tag "destination", raw("<option>NYC</option><option>Paris</option><option>Rome</option>"), disabled: true
#=> <select disabled="disabled" id="destination" name="destination"><option>NYC</option><option>Paris</option><option>Rome</option></select>