Research by leventhal and his colleagues (1967) was described in the text. in the experiment, the researchers showed some smokers a graphic film about lung cancer and gave them a pamphlet with instructions on how to quit; other smokers received either the pamphlet alone, or watched the grisly film. after three months, those smokers who received only the pamphlet with instructions were smoking significantly more than those who both saw the film and received the pamphlet. what is the dependent variable of this research? a. information alone is not sufficient if people are not motivated to use it.
b. fear alone is not sufficient if people don't know how to reduce it.
c. a message must be relevant to people if they are to pay attention to it.
d. fear, like other negative moods, encourages people to pay attention to the message.

I would say that the best answer to the question: What is the dependent variable of this research, would be: A) Information alone is not sufficient if people are not motivated to use it.

Explanation:

A dependent variable is the one in research whose result will entirely depend on the outcomes of the independent variables. In this case researchers decided to use different means of information on smoking to achieve the reduction of their smoking. While to a group they showed them a video and gave them a pamphelt with instructional information on how to quit, to the other group they subdivided it and gave one portion just the video, and the other just the pamphlet. In the end, the result was that during follow-up, researchers found that the group with the least reduction in smoking was the one to whom only the pamphlet had been given. This result showed that the pamphlet, which was the information only, was not enough to encourage smokers to leave the habit. It became evident that a factor of fear was necessary to achieve that final goal.