
Passage: The traditional view is that most of the methane that causes Greenhouse Effect comes from wetlands and the digestive tract of ruminants, but green plants that can absorb carbon dioxide also release methane. Scientists have found that the astonishing result is that the annual amount of methane released by the world's green plants is 60 million to 240 million tons, accounting for 10% to 40% of the world's total annual methane emissions, of which about 2/3 come from tropical areas with rich vegetation.
Question: All but which of the following statements can support the views of scientists?
A. A.If green plants are not taken into account, excluding all other factors, there are still a large number of sources of methane in the world that cannot be explained
B. B.German scientists have observed methane clouds over the rainforest by satellite, a phenomenon that cannot be explained by known global sources of methane
C. C.American chemists analyzed air samples taken from the Venezuelan savannas and concluded that the amount of methane released by vegetation in this area was 30 million to 60 million tons
D. D.Some scientists stressed that the recent increase in methane levels and global warming have nothing to do with forests and plants are innocent
Answer: