A Researcher Wants to Assess the Effects of Varying Amounts

Multiple Choice

A researcher wants to assess the effects of varying amounts of alcohol on ratings of perception of friendliness. Three groups of people are given either 1, 2, or 3 beers to drink. Three more groups of people are given either 1, 2, or 3 non-alcoholic beers to drink. Then, all participants are shown a series of pictures of people's faces and are asked to rank the perceived friendliness of each face on a scale from 1 to 10. Each face was presented for 5 seconds. In this experiment, the dependent variable is:

A) the number of groups.
B) whether or not the beer had alcohol in it.
C) how long each participant was allowed to look at each face.
D) ratings of perceived friendliness.