780 Participants Suffering from Depression Were Randomly Assigned to One

Multiple Choice

780 participants suffering from depression were randomly assigned to one of three groups.Over a four-month period,the first group received a low dosage of an experimental drug,the second group received a high dosage of the drug,and the third group received a placebo.At the end of the period each participant rated their mood on a scale of 1-10.Identify the factor(s) in the experiment and the number of levels for each.

A) The experimental drug (3 levels)
B) The dosage of the drug (3 levels)
C) The experimental drug (3 levels) ,mood (10 levels)
D) Mood (10 levels)
E) Placebo,low dosage,high dosage (3 levels)