In which scenario would you use Alibaba Cloud's Anti-DDoS service?

Using Alibaba Cloud's Anti-DDoS service is essential in scenarios that involve protecting resources from Distributed Denial of Service (DDoS) attacks. DDoS attacks are designed to overwhelm a target, such as a website or a network resource, with a flood of traffic, rendering it unavailable to legitimate users. The Anti-DDoS service provides a shield against such attacks by disseminating and filtering traffic, ensuring that only legitimate requests are allowed through while malicious traffic is mitigated.

In this context, the other options do not align with the primary function of the Anti-DDoS service. For instance, backing up critical data involves data storage solutions rather than traffic management and protection mechanisms. Similarly, deploying machine learning models is focused on computational resources and algorithm training, which does not directly relate to DDoS protection. Lastly, managing customer access pertains to authentication and authorization features rather than security measures against traffic overload. Therefore, the most relevant and appropriate scenario for using the Anti-DDoS service is to safeguard resources from DDoS attacks.