A Study Was Done to Investigate the Effect of 'Motivation

Multiple Choice

A study was done to investigate the effect of 'motivation to quit' on the success rate of a new intervention developed to reduce the number of cigarettes smoked per day in a group of smokers. Looking at the graph below, what can we say about the relationship between motivation to quit and the success rate of the intervention?

A) Whether a person wanted to quit smoking had no effect on the success of the smoking intervention.
B) There were the same number of people who wanted to quit smoking as who didn't.
C) We can't say anything about the success of the intervention because the graph does not take into account the number of cigarettes smoked per day pre-intervention.
D) The medians were the same in people who wanted to quit smoking and those that didn't.