I think that It is C, adverb clause
The release of more polluting gases to our environment
I had to look for the passage and here is my answer:
Based on the passage attached to this in which the one who narrates in it is Gulliver, the event that is being described in this passage is Gulliver's plan to escape from Lilliput. Lilliput is one of the fictional places in "The Gulliver's Travel" that was written by Jonathan Swift. The answer for this would be the first option.
Answer: B
“They was” is not correct.
