What is the effect of the author's choice to insert historical background about natural gas in the middle of the passage?
It emphasizes the unpopularity of natural gas for many years by citing the lack of
interest in building pipelines.
It establishes the usefulness of natural gas for building fires in both ancient and modern
times.
It highlights the difficulty of obtaining natural gas by relaying the challenges of reaching
underground supplies.
It stresses the importance of natural gas by describing the different ways in which
natural gas has been extracted and used.