An advertiser wants to simulate a what-if scenario involving changes to both their ROAS targets and their budgets simultaneously. Which tool is designed for this long-term planning?

The Performance Planner is the correct tool because it allows advertisers to forecast how changes to bids, budgets, and other campaign settings will impact performance metrics like conversions and conversion value over a future period. It's specifically designed for long-term planning and simulating "what-if" scenarios, including simultaneous adjustments to ROAS targets (through bid changes) and budgets. The Bid simulator shows how different bid changes might affect clicks, costs, and impressions for a single campaign, but it doesn't account for budget changes or long-term planning across multiple campaigns. Recommended Investment Strategy is not a standard Google Ads tool. Optimization score provides recommendations to improve campaign performance but doesn't simulate future scenarios based on budget and bid changes.