to weaken the argument, we should ground that this increase in wages will indeed drive the inflaltion rate up.
In choice (b), it doen't denying anything in the reasoning above, i.e. very small proportion of all Kirfandic workers are currently receiving less than KD5.50 per hour
---> the impact on wages will probably be negligible. Even though some workers were paid less than KD5.00, it still doesn't have impact on the wages as a whole (or the impact is negligible)
In choice (c), it says that many businesses must pay their trained workers a higher wage than minimum wages. Thus, such businessese previously paid their trainees >KD5.00 per hour. Now they have to pay their trainees >KD5.50 per hours. (trainees are not workers). In this case, many businesses hire trainees so that it is not a some proportion that can be negligible. The argument is weakened.