Study the classification chart below.
Which one of the following sets of organisms best represent P, Q, R and S ?
P | Q | R | S | |
A | Algae | Starfish | Frog | Salmon |
B | Yeast | Amoeba | Human | Lizard |
C | Amoeba | Yeast | Cow | Frog |
D | Hydra | Planaria | Sparrow | Frog |