As the temperature rises, the chance of a tropical rainforest being struck by lightning and causing a fire will also increase. However, current monitoring shows that although the American rainforests are struck by lightning more frequently, they have not triggered more forest fires. The researchers believe that this may be related to a large increase in vine plants in the rain forest in recent years. Which of the following, if true, best supports the above conclusion? ['Lightning strikes often cause fires in temperate forests, but tropical rain forests do not cause major fires due to high humidity.', 'In 1968, the coverage rate of vine plants in the tropical rain forest was 32%, and the current coverage rate has reached as high as 60%, and some areas even exceed 75%.', 'The vine stem has a lower resistance than the branch, and can conduct lightning like a lightning rod on a building, allowing most of the current to be conducted from its own stem.', 'Lightning strikes such a large-scale and extremely fast discharge, first destroyed the external vine plants, and the trees in the middle were protected.']