将类和样式添加到下拉列表轨道

Question

我有这段代码

 <%= f.select "banker_assignment[banker_assignment_status_id]", options_from_collection_for_select(@banker_assignment_statuses, :id, :assignment_status, @banker_assignment.banker_assignment_status.id),  data: { selected: @banker_assignment.banker_assignment_status.id }, { :class => 'form-control single-select' }, { :style => 'float: right' } %>

我想将以下类和样式添加到下拉列表中，但我总是收到错误

syntax error, unexpected ',', expecting =>
...'form-control single-select' }, { :style => 'float: right' }...
...                               ^

我如何摆脱这个错误？

谢谢