We’re in a stage _____ it’s still too early to say who will win the most votes and become the new President.

A．that

B．where

C．which

D．what

有关OLT说法正确的是（）。

A.通常放置在中心机房

B.OLT即光网络终端

C.通常放置在用户侧

D.无源光分路器