Which of the following statements about Alibaba Cloud Log Service is correct?

The statement that logs are saved across three separate physical servers accurately reflects a key feature of Alibaba Cloud Log Service, which is designed to ensure high availability and data durability. By distributing logs across multiple physical servers, Log Service enhances data protection against hardware failures and ensures that logs are consistently accessible and reliable. This design leverages a distributed architecture that is common in cloud services to provide resilience against potential data loss, making it a robust option for logging solutions.

The other statements, while intriguing, are either misleading or overly restrictive. For instance, Logtail is indeed capable of collecting logs from various sources, including system files, which contradicts the assertion in option A. The reference to physical backups in option B oversimplifies the data management capabilities of Log Service, as it supports various redundancy and backup strategies inherent in cloud infrastructures. Lastly, stating that Log Service is only suitable for small applications is inaccurate; it is designed to scale with the needs of applications of all sizes, from small projects to large enterprise-level systems, thus demonstrating its versatility and capability in diverse scenarios.