For SIE exam purposes, a person who beneficially owns 10% or more of an issuer’s outstanding voting stock is treated as an affiliate or control person of the issuer. Affiliates are subject to restrictions when selling control or restricted securities under SEC Rule 144. Rule 144 provides a safe harbor for resale of restricted and control securities if specific conditions are met, such as holding-period requirements, current public information, volume limits, manner-of-sale conditions, and notice filings, depending on whether the seller is an affiliate. Choice C is correct. One percent is commonly associated with the volume limitation under Rule 144 for affiliates, not the threshold in this question. Five percent and fifteen percent are not the standard SIE-tested affiliate percentage. The SIE outline includes control and restrictions under equity securities and specifically references SEC Rule 144. This question tests whether the candidate recognizes the regulatory treatment of control persons and the resale limitations that apply when insiders or controlling shareholders dispose of issuer securities. Reference: Understanding Products and Their Risks; Equity Securities; Control and Restrictions; SEC Rule 144.