当遭遇严重颠簸和/或者山地波导致的多大的高度偏差时，飞行员应向管制员报告"由于颠簸，不能保持RVSM"? How much altitude deviation caused by severe turbulence and/or mountain wave should the pilot report to controller "UNABLE RVSM DUE TO TURBULENCE"?
A.约45米（150英尺）或以上 45 meters (150feet) or above
B.约60米（200英尺）或以上 60 meters (200feet) or above
C.约90米（300英尺）或以上 90 meters (300feet) or above
正确答案是B