I am absolutely sure that the way how can a moving coil galvanometer can be made into a dc ammeter is of course by connecting a. low resistance across the meter. You should remember that you must connect <span>a shunt resistor straight across the galvanometer. Do hope this answer will help you! Regards.</span>
relation between potential difference and electric field is given as

so here we know that
d = 3 cm



So now when plates are separated to 4 cm distance carefully
the potential difference between them will change but the electric field between them will remain constant
So at distance of 4 cm also the electric field will be E = 1000 N/C
Answers A and C can be automatically eliminated because evaporation has to do with the water cycle and magnetism has to do with electric current and such. Next we can eliminate B or distillation because it also has to do with water/liquids. Therefore, the answer is D or filtration because it is the only answer left.
I hope this helps!