Opportunity Update Reminders is a specific, automated feature in Salesforce designed exactly for this purpose. When enabled, it allows managers to automatically send an email to their direct reports with a list of their open opportunities. The email serves as a prompt for the reps to review their deals and ensure close dates, amounts, and stages are current. This is more effective than a general Scheduled Report (Option D) because it is a purpose-built notification system that can be configured by the manager. Big Deal Alerts (Option C) are for high-value deal notifications, not general pipeline hygiene. Similar Opportunities (Option A) helps with sales strategy but does not encourage record updates.