Answer :
The book would include the development of the large increase in business profits due to government contacts as support for the statement. That is the only economic selection given in your multiple choice answers.
I believe the answer is: steep increase of business profits due to government contracts
The contracts that created by the government provide the private sectors with several projects that they can take on that might increase their profit. Example of such contract would be things such as contract to help the government building a bridge or contract to help the Government in developing a certain technology.