No, we are saying A.
As stated in the original post, with 25% more survey points, progress is 20% faster (completed in 80% of normal time). Therefore with 100% more survey points, progress is 50% faster (completed in half the time).
No it's not.
If speed for a given action is (x), if it moves 50% faster it moves at a speed of 1.5(x), and will complete in 2/3rd of the time compared to the same action moving at speed (x).
That the action completes within 2/3rd of the time when the points per unit of time accrue at twice the rate for the same action at speed (x) implies a non-linear relation between the speed of point accrual and the speed of completion of the action.
Instead, with 100% more survey points per unit of time, progress per unit of time is also 100% greater, and moves at twice the speed of normal. This means that the time it takes to complete the survey is half of normal.
A factor that would allow instant completion of surveys would be infinitely large, although I'm sure that there's a multiplier value where a survey missile can survey anything within a single 5 second pulse, at which point larger values are no longer relevant because the game won't implement orders without running the code and the code isn't run without pressing the next turn button.