High school students signed up to be subjects in a psychology experiment. When they arrive, they are told that interviews are running late, and they are taken to a waiting room. The experimenters have placed a sign in the waiting room next to a button that says, "Do not push under any circumstances." Some subjects are alone in the room and others are in pairs; these are the treatments being compared. Will the subject push the button? The students agreed to take part in an unspecified experiment, and the true nature of the experiment is explained to them afterward. Does this meet the requirement of informed consent? Explain.

a
No, because they did not know the nature of the experiment before participating

b
No, because they had to wait for the interviews

c
Yes, because they agreed to participate in an experiment

d
Yes, because they are not forced to push the button

e
Unable to determine whether subjects consented to experiment.