This requirement involves complex Marketing Automation that goes beyond the capabilities of standard Salesforce transactional tools. While Salesforce Flow (Option C) can handle time-based triggers, it cannot natively track and react to specific "website visits" or web behavior without significant custom coding or integration.
Account Engagement (formerly Pardot) is the ideal solution for this scenario because of its specialized feature set:
Website Tracking: Account Engagement uses a tracking code (cookie) to monitor constituent behavior on the nonprofit's website. This allows the system to "know" which pages a member visited (e.g., a "Benefits" page vs. a "Donate" page).
Engagement Studio: This is a visual journey builder. A consultant can create an "Automated Renewal Program" where the system waits 30, 60, 90, and 180 days.
Dynamic Content: At each step of the 30/60/90/180-day cadence, the system can use Dynamic Content to swap out parts of the email template. If a member visited the "Member Events" page recently, the renewal email can automatically include a section about upcoming events to increase the relevancy of the appeal.
Recency and Frequency: The tool can segment members based on how recently they visited the site, ensuring the messaging is timely and tailored to their current level of engagement.
Why other options are incorrect:
Engagement Plans (Option B): These create internal Tasks for staff, not automated external emails with web-tracking logic.
Flow (Option C): While it can send emails, it lacks the built-in web-tracking and high-volume marketing analytics provided by Account Engagement.
Apex (Option A): This would be an expensive, high-maintenance custom solution for a problem that is solved out-of-the-box by a marketing automation platform.