Final answer:
It is true that the COSO framework assesses a company's internal control effectiveness, as evidenced by its adoption following corporate scandals that prompted the enactment of the Sarbanes-Oxley Act to protect investors.
Step-by-step explanation:
The statement that the framework used to assess the effectiveness of a company's internal control was established by the Committee of Sponsoring Organizations of the Treadway Commission is true. This framework is widely known as COSO and it provides a model for evaluating the design and effectiveness of internal controls, including those related to financial reporting and compliance.
The importance of such frameworks became even more evident after major accounting scandals involving corporations like Enron and WorldCom, which led to the creation of the Sarbanes-Oxley Act in 2002. The purpose of the Sarbanes-Oxley Act was to increase investor confidence in the financial information provided by public corporations and to protect investors from accounting fraud. Corporate governance structures, including the board of directors, auditing firms, and outside investors, play critical roles in overseeing and validating the financial integrity and transparency of corporations.