app/views/admin/registrars/form/_preferences.html.erb
<div class="panel panel-default">
<div class="panel-heading">
<%= t '.header' %>
</div>
<div class="panel-body">
<div class="form-group">
<div class="col-md-4 control-label">
<%= f.label :language %>
</div>
<div class="col-md-7">
<%= f.language_select :language, nil, {}, required: true, class: 'form-control' %>
</div>
</div>
</div>
</div>