Hi crrice1!
Yes, "appreciable" means basically the same thing as "significant" here.
This is a conditional reasoning question. The first sentence presents us with an "unless" statement which can be diagrammed as follows:
New computer system significantly increase efficiency
employees adopt new ways of working
Then the author tells us that at the Ministry of Transportation the employees are NOT going to adopt new ways of working. Using the contrapositive of the above statement, that gives us:
Employees adopt new ways of working New computer system significantly increase efficiency
So our prephrase heading in should be:
New computer system significantly increase efficiency
Answer choice (A) matches this prephrase because, again, "appreciable" basically just means significant enough to be noticed.
For answer choice (E), we don't have any evidence that it will be easy for the employees to learn the new system. Even though it's designed to fit the ministry's existing ways of working, that doesn't mean it will be easy to learn. Maybe they're currently on a paper only system. They may just be moving all that functionality to the computer system, but if their employees don't know how to use computers very well or if the system is designed poorly, it might still be difficult to learn.
Hope this helps!
Best,
Kelsey