--- it have been wrong directions from the control room that

选B,Could.
对过去情况进行【可能性推测判断】,【疑问句】中只有【can,could】两种形式.
原句本身是个【一般疑问式的强调结构】,
【Could】 it have been wrong directions from the control room 【that】 caused the air crash?
句意：可能是来自控制室的错误指示导致这起飞机坠毁事件的吗?
如果还原为陈述形式,答案会有所变化—
It 【must_】_ have been wrong directions from the control room that caused the air crash.
一定是来自控制室的错误指示导致这起飞机坠毁事件.