某光线从玻璃入射到空气中发生全反射的临界角是45°,则这种玻璃的折射率为( )
A <img width="35" height="57" src="https://www.beizhujiaoyu.com/uploads/202208/20210727163331_3374.gif" /> B <img width="32" height="28" src="https://www.beizhujiaoyu.com/uploads/202208/20210727163332_2583.gif" /> C <img width="30" height="30" src="https://www.beizhujiaoyu.com/uploads/202208/20210727163333_4145.gif" /> D 2