What is random assignment

A)  Subjects are free to choose which group or condition they would like to be in. 
B)  All variables have an equal chance of being assigned to the experimental condition. 
C)  All people have an equal likelihood of being selected from the study. 
D)  All subjects have an equal chance of being assigned to any of the groups or conditions.

Random assignment refers to the process by which participants are assigned to different groups or conditions in a study, with all participants having an equal likelihood of being assigned to any group or condition. This helps to ensure that any differences observed between groups are due to the experimental manipulation of the independent variable, rather than pre-existing differences between groups. Therefore, D is the correct answer as it best describes random assignment.