Final answer:
Insider reports must be filed by insiders, such as corporate officers, directors, or significant shareholders. In this scenario, Cathy is definitely required to file because she is president of a company owning a significant percentage of Waddington Woolworks. The requirement for William and Donald depends on their stake in the company and access to non-public information.
Step-by-step explanation:
In the context of securities trading and regulation, certain individuals such as corporate insiders, who have access to significant, non-public information, are required to file insider reports with the securities administrator when they trade their company's securities. An insider typically includes a company's officers, directors, and significant shareholders (usually those owning more than 10% of any class of outstanding shares). Based on the information provided, Cathy, as president of Canadian Carpet Company, which owns 15% of Waddington Woolworks, and Donald, assuming he holds a similar position or ownership, would be required to file insider reports. William, as a foreman, would typically not fall within these categories unless he also has a considerable stake in the company or if he has received significant, non-public information that could affect stock prices.
Therefore, to answer the question, it would be options 2) Cathy and Donald, if Donald holds a significant stake or position in the company, or 4) All three are required to file, if William's role as foreman provides him with access to important non-public information or if he owns a significant amount of shares.