阅读理解
(Mr. Zhang is showing Wei Fang and Li Lei a modern factory.)
Mr. Zhang: You can’t see many workers here, but you can see a lot of robots. Look, that robot has two big hands.
Wei Fang: How strong it looks!
Mr. Zhang: Yes. It does much work for us.
Li Lei: There are so many big boxes here. What are the robots doing?
Mr. Zhang: They are making fridges.
Wei Fang: How fast they are working!
Li Lei: How much time do they need to make a fridge, Mr. Zhang?
Mr. Zhang: About five minutes.
Wei Fang and Li Lei: Only five minutes! What a modern factory it is!

阅读材料，回答问题

材料一：目前中国汽车工业的集群化效应初步显现，基本形成了以东北、京津、中部、西南、长三角和珠三角为代表的六大汽车产业集群（见下图）。

材料二：资料显示，中国汽车从年产量不足200万辆，激增到超过850万辆，只用了6年时间。目前中国汽车市场增长率保持在25%左右，中国在全世界汽车产业的排序已经从第8位升至前3位。目前中国已经成为世界第二大汽车消费国，第三大汽车生产国，第一大潜在市场。

已知点$P$在曲线$y=\frac{4}{e^x+1}$上，$\alpha$为曲线在点$P$处的切线的倾斜角，则$\alpha$的取值范围是（　　）