An introductory sentence for a brief summary of the passage is provided below. Complete th

e summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points. Originally, natural gas was not considered a useful commodity and it has only become a major source of energy in the last century. ______ ______ ______ Answer Choices A. Natural gas differs from other fossil fuels in that it is not found in underground deposits. B. Natural gas is extracted from both associated and non-associated sources, and there are many different varieties. C. Some deposits of natural gas contain high concentrations of impurities such as sulfur and cannot be used commercially. D. Because it burns cleaner than coal and oil, natural gas is much less damaging for the environment. E. One of the main drawbacks in the use of natural gas is that it cannot be piped across oceans. F. Natural gas is an appealing alternative to other fossil fuels because it is cheaper, more easily transported, and more abundant.