我国采用的光同步数字速率等级是（）
A2Mb/s，8Mb/s，34Mb/s，140Mb/s
B1.5Mb/s，6.3Mb/s，45Mb/s，274Mb/s
C155Mb/s，622Mb/s，2.5Gb/s，10Gb/s
D52Mb/s，155Mb/s，466Gb/s，622Mb/s……10Gb/s
A2Mb/s，8Mb/s，34Mb/s，140Mb/s
B1.5Mb/s，6.3Mb/s，45Mb/s，274Mb/s
C155Mb/s，622Mb/s，2.5Gb/s，10Gb/s
D52Mb/s，155Mb/s，466Gb/s，622Mb/s……10Gb/s