Railsのセレクタoptions_for_selectでクラスを指定する

html_optionsで指定する。

<%= o.select :weighting, options_for_select([
  ["Correct", "4", {:class=>"bold"}],
  ["Good", "3"],
  ["Average", "2"],
  ["Poor", "1"], 
  ["Incorrect", "0", {:class=>"bold"}] ], @whatever.weighting.to_s), {},
  html_options = {:class => "listBox", :style=>"float:left;"} %>