单项选择题 <img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251103/8790336_0.jpg"><br/> <img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251103/8790336_0_1.jpg"><br/> <br/> A. 2267r/min;B. 28l5r/min; C .3000r/min D. 3120r/min