The correct answers are B and D. Option B is correct because AWS provides a highly available and secure infrastructure that can help improve service level agreements (SLAs), thereby reducing the risk of unplanned downtime. This results in a more reliable service for customers and minimizes business risk. Option D is correct as migrating to AWS can reduce IT costs related to infrastructure. AWS operates on a pay-as-you-go pricing model, which means businesses only pay for the resources they use, without the need for upfront capital investments in hardware. This can lead to significant cost savings, allowing businesses to reallocate their budget to other strategic areas. Option A is incorrect because while AWS can enable mobile access to applications, it does not automatically make them available on mobile devices. Option C is incorrect because migrating to AWS does not eliminate the need to plan for high availability and disaster recovery; it simply provides the tools and services to do so more effectively. Option E is incorrect because migration to AWS does not require companies to rearchitect and rewrite all enterprise applications; it offers flexibility to lift-and-shift existing applications or modernize them as needed.