The word "extensive" most likely means as used in paragraph 12 is Widespread.
The 'paragraph 12' which is talking about in the question is from the story " An overview of the great depression" by Jessica McBirney.
The word "extensive" come in a para "At the beginning of the financial problem, few people predicted the crisis would last over a decade , but the problem were more extensive and much deeper than analysts realized at first.
The word extension means having considerable extent , which has a synonym widespread that is given in the option. Therefore, the correct answer is option D.
