skill-assessment-app/app/views/quiz/_checkbox.html.erb

<% 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),
                      data: { last: Array(question.answer).include?(option) ? 'checked' : '' }
                    }
    answers = answer.try(:answer) || answer
  %>
    <div class="form-group-multiples">
      <%= form.check_box(:answer, checkbox_html, option, '') %>
      <%= form.label(option_id, option) %>
    </div>
<% end %>

<%= render partial: "quiz/answer_errors", locals: {question: question, answer: answer} %>