以下哪项是品牌提升测试中可以衡量的指标？

Brand lift studies measure the impact of advertising on brand perception and consumer attitudes. All the listed options are relevant metrics that can be assessed in such a study. Click-through rate (CTR) indicates engagement with the ad. Total impressions show the reach of the campaign. Return on Ad Spend (ROAS) measures the revenue generated for each dollar spent on advertising, reflecting the financial efficiency. Ad recall measures how memorable the ad is to the audience. These metrics collectively provide a comprehensive view of an ad campaign's effectiveness in influencing both immediate actions and broader brand perception.