Answer:
The correct answer is letter "C": open source of information about publicly-traded companies.
Explanation:
After going public, a company must meet certain obligations periodically to remain with its status and to comply with the exchange trade minimum requirements. One of those requirements implies filing a 10-K form every year in which the firm describes in detail its annual performance mainly for the interest of investors.
Besides, the organization has to report financial statements and any other financial report on the course of its operations during the previous period. 10-K forms are uploaded in the Security and Exchange Commission (SEC) web age for the public use of individuals.