The process whereby individuals are assigned to research groups by chance is known as:

A) randomization
B) population
C) experimentation
D) sampling
E) variation

Randomization involves assigning individuals to groups by chance, which helps to control for potential confounding variables and increase the validity of research findings. Population refers to the entire group of individuals being studied, while experimentation involves manipulating variables to test hypotheses. Sampling involves selecting a subset of the population for study, and variation refers to differences that exist within a population or between groups.