正解:C
Resource exhaustion is most likely occurring on the server. Resource exhaustion is a condition where a system runs out of resources, such as CPU, memory, disk space, or network bandwidth, due to excessive demand or consumption by one or more processes. Resource exhaustion can cause performance degradation, system instability, or denial-of-service. The server statistics show that the CPU usage is 100%, the memory usage is 99%, and the disk usage is 98%. These indicate that the server is under heavy load and has little or no resources available to handle incoming requests or perform other tasks.