祈使句表达建议与劝告 — 英语选择题

班会讨论'绿色出行'，老师要求大家用祈使句向同学们提出建议或劝告。下面四位同学的发言中，完全符合祈使句表达建议与劝告规范的一项是（　　） A. Don't to drive cars to school. You can ride a bike instead. B. Please turn off the lights when the classroom is empty. C. Let's to plant more trees around our school. D. Turn on the tap all the time to save water.