The correct answer is Script inclusion that stores malicious code in the website’s database, as this reflects the persistent nature of the attack, where the malicious code is stored on the server and executed for every user that accesses the infected page. This persistence allows the attacker to perform actions like stealing session cookies or delivering malware without having to re-inject the XSS code with each visit.

Other potential payloads like reflected code or self-executing scripts would not achieve persistence, as reflected XSS attacks are only effective when a victim clicks on a specially crafted link, and self-executing scripts would only run on page load without further interaction with the user.