The correct answer is A) He uses the words 'contaminated' and 'evacuated' to express his seriousness about the danger.
The author's word choice most likely suggests the following: He uses the words 'contaminated' and 'evacuated to express his seriousness about the danger.
That is why it is so important that when you are writing a text like this, you use the proper language and correct grammar to indicate what you are meant to say. There is also important that you have enough information, culture, and background about the issue at hand in order to express yourself with the best terms possible and transmit the reader the idea or emotion you want to transmit.
The other options of the question were B) He explains that the leak occurred two decades later to show that this is not a major concern. C) He uses the words 'abandoned' and 'hall-finished to show that the project did not proceed as planned. D) He criticizes the reckless practice of dumping chemical waste in a landfill.