Many mountain climbers regard climbing Mount Everest as the ultimate achievement. But climbers should not attempt this climb since the risk of death or serious injury in an Everest expedition is very high. Moreover, the romantic notion of gaining "spiritual discovery" atop Everest is dispelled by climbers' reports that the only profound experiences they had at the top were of exhaustion and fear. Which one of the following principles, if valid, most helps to justify the reasoning above? ['Profound spiritual experiences can be achieved without undergoing the serious danger involved in mountain climbing.', 'Activities that are extremely dangerous ought to be legally prohibited unless they are necessary to produce spiritual enlightenment.', 'Dangerous activities that are unlikely to result in significant spiritual benefits for those undertaking them should be avoided.', 'Mountain climbers and other athletes should carefully examine the underlying reasons they have for participating in their sports.']