When checking a mooring line，you should（）.

A.ensure the bight is not fouled between the ship and the dock by taking up slack

B.pay out slack smartly and keep free for running

C.secure more turns to hold the line against any strain，then clear the area

D.surge the line so that it maintains a strain without parting

根据《液压爬升模板工程技术规程》，爬模装置的制作中，导轨平直度的允许偏差是（）mm。

A.2

B.±2

C.±3

D.±5