In an experiment, one group of volunteers was shown words associated with money, such as "salary, whereas another group was shown neutral words. Afterward, individuals in both groups solved puzzles unrelated to money. Those who had been shown words associated with money were much less likely to request or offer help with the puzzles. The researchers concluded from this evidence that preoccupation with money makes people less cooperative.
Which of the following is an assumption the researchers' reasoning requires?
(A)At least some of the volunteers were preoccupied with money before being shown the words.
Being shown the neutral words did not cause the volunteers to become preoccupied with subjects other than money.
Most of the volunteers who were shown neutral words requested or offered help with the puzzles.
Most of the volunteers in both groups succeeded in solving the puzzles, either with or without help.
The volunteers who were shown neutral words were, on average, less preoccupied with money while solving the puzzles than the other volunteers were.