<%
  question.input_options.each_with_index do | option, i |
  option_id = "#{question.question_id}_#{i}"

  checkbox_html = {class: 'checkbox',
                      id: "answer_#{option_id}",
                    name: "answer[checkbox][]",
                 checked: Array(question.answer).include?(option)
                  }
%>
  <div class="form-group-multiples">
    <%= form.check_box(:answer, checkbox_html, option, '') %>
    <%= form.label(option_id, option) %>
  </div>
<% end %>

<% if flash[:error].try(:include?, question.to_i) %>
  <div class="error">Please select an answer.</div>
<% end %>
