在图4-2-14所示机构中，曲柄OA以匀角速度ω0转动，且OA＝r，又AB＝AC＝。当曲柄OA与连杆AB位于同一铅垂线上时，OA⊥OC，此时连杆AB的角速度为（　　）。图4-2-14

B、<img width="86" height="37" src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/34cdd4f7-e232-420c-987d-5a813f8d4700.jpg" />

C、<img width="83" height="37" src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/23ad9bee-1948-4583-9a9c-4232dfe36bd8.jpg" />

D、ω₀