客户有一个新的音频广告采用了有保证的程序化交易，您的同事想对该交易进行品牌提升效果研究 (BLS)。在 Display & Video 360 中进行品牌提升效果研究时，他发现该交易未产生具有显著意义的结果。 原因可能是什么？

The correct answer is that Brand Lift Studies (BLS) cannot be measured for guaranteed programmatic deals. Display & Video 360's Brand Lift Studies are designed for open auction and private auction deals, where there's more flexibility in audience targeting and exposure to control groups. Guaranteed programmatic deals involve a direct agreement for a fixed inventory and price, which limits the ability to create the necessary control and exposed groups for a statistically significant BLS. Display & Video 360 does support Brand Lift measurement, so that option is incorrect. Brand Lift can be measured for audio ads, making that option incorrect. While BLS results aren't instantaneous, the issue here isn't a delay but a fundamental incompatibility with the deal type, so that option is also incorrect.