Which of the following is the recommended optimization strategy for line items that are performing and delivering above goal?

The recommended strategy is to maintain bids and frequency caps while shifting budget from underperforming line items to those performing above goal. This approach maximizes the campaign's overall efficiency and return on ad spend. By maintaining current bids and caps, you avoid overspending or over-exposing the audience, which could lead to diminishing returns or increased costs. Shifting budget ensures that more funds are allocated to the most effective parts of the campaign, driving better results without increasing the total campaign budget. Increasing bids and frequency caps could lead to higher costs per conversion or diminishing returns. Taking no action misses an opportunity to optimize campaign performance.