Answer
See explanation below.
Work Step by Step
a) No of particles decreases with dilutions.Thus,
C depicts it better because , the dilution causes decrease in population by 3 times approx.
b) No of particles decreases with dilutions .Thus,
B depicts it better because , the dilution causes decrease in population by 2 times , ie from 12 to 6
c) No of particles decreases with dilutions .Thus,
D depicts it better because , the dilution causes decrease in population by 4 times , ie from 12 to 3