The same task triggers different levels of awareness of one' s surroundings, called environmental awareness, in different individuals. Mathematical puzzles, for example, cause most people to increase such an awareness. Some people -- those who formulate the answer visually, imagining the numbers in their mind' s eye -- will, in an attempt to freeze the picture, experience a decrease in environmental awareness while solving the puzzle. Other people' s environmental awareness may rise during the exercise, because their brains are signaling a rest at the end of every stage of problem solving. Which one of the following is most strongly supported by the information above? ['People who visually formulate answers differ from other problem solvers in that the former are aware of their surroundings.', 'People tend to be more aware of their surroundings when solving mathematical problems than when solving nonmathematical problems.', 'There are some people for whom mathematical puzzles do not cause an increase in their level of environmental awareness.', "Mathematical problem solving requires frequent periods of rest in the form of increased awareness of the problem solver's surroundings."]