一家零售公司需要为其应用广告系列上传广告素材资源。 图片素材资源可以使用何种宽高比？

Google Ads App campaigns support multiple aspect ratios for image assets to maximize reach across various ad placements. The correct aspect ratios are 1:1 (square), 1.91:1 (landscape), and 4:5 (portrait). These ratios ensure your ads display optimally on different devices and platforms, such as in-app placements, search results, and YouTube. Other options are incorrect because they either omit a supported aspect ratio or include one that is not officially supported for App campaigns, like 1.75:1. Providing assets in these three standard ratios helps Google Ads automatically optimize and serve your ads effectively.