Recently, your networking team enabled Cloud CDN for one of the external-facing services that is exposed through an external Application Load Balancer. The application team has already defined which content should be cached within the responses. Upon testing the load balancer, you did not observe any change in performance after the Cloud CDN enablement. You need to resolve the issue. What should you do?

A. Configure the CACHE_ALL_STATIC caching mode on Cloud CDN to ensure Cloud CDN caches all static content as well as content defined by the backends. B. Configure the FORCE_CACHE_ALL caching mode on Cloud CDN to ensure all appropriate content is cached. C. Configure the USE_ORIGIN_HEADERS caching mode on Cloud CDN to ensure Cloud CDN caches content depending on responses to requests from the backends. D. Configure the CACHE_ALL_STATIC caching mode on Cloud CDN to ensure Cloud CDN cache content depending on responses to requests from the backends.