It is important to build credibility by citing sources. Business writers follow a narrative pattern in business documents. Which of the following examples is the best way to build your credibility in a business document?

a$)$ Only $57$ percent of American adults have basic financial literacy skills, putting it in $4$th place among nations with advanced economies.

ch

b$)$ Standard and Poor's $2014$ study on global financial literacy found that only $57$ percent of American adults had basic financial skills, putting the U$.$S$.4$th among nations with advanced economies.

c$)$ A study on the financial literacy among American adults show that the U$.$S$.$ ranks $4$th among $144$ nations. $($Standard & Poor, $2014).$