当光纤测试距离≤80km时,脉宽和测试平均时间应设置为()?

当光纤测试距离≤80km时,脉宽和测试平均时间应设置为()?

A.300ns/30s-1min

B.1us/30s-1min

C.1us/1.5min

D.3us/3min

正确答案是C