In conducting an experiment, the experimenter divides a sample group of 60 children into two groups of 30 called group A and group B.
To make sure the two groups are similar in terms of age, IQ. and so on, the experimenter will assign people to either group A or B using a/an ______ assignment procedure, such as a coin toss, where heads sends a subject to group A and tails sends a subject to group B.

A. independent

B. experimental

C. random

D. subjective