Shanghai Disneyland has started to be built and it will be open__five years.

问题描述:

Shanghai Disneyland has started to be built and it will be open__five years.
A in B for C from D before

A
in +一段时间,常与一般将来时连用,因为it will be open是一般将来时,而时间状语与前半句的现在完成时无关,故A对