Sorry I did not take photo on day 4 and I did not update the progress yesterday.
Now Grass B grows well and we see no differences in grass between microwaved watered ones and normal watered ones yet.
Just remind that I have only water those grass once, as I see no needs of watering it everyday. If the soil is wet, why should I water it?
It seems now grass A become thirsty (shrink a little bit), I will water them tomorrow.