Which of the Following Methods of Assigning Participants to Groups

Multiple Choice

Which of the following methods of assigning participants to groups in an experiment is the best example of random sampling?

A) putting the girls in one group and the boys in another
B) making sure that children are able to select the group to which they want to belong
C) putting all children's names in a hat and drawing names to form the groups, even if this results in having unequal numbers of boys and girls in the groups
D) having the teacher assign children to groups in order to best separate friends from each other