— Hello! I'd like to speak to Jim.

— _____ [ ]

A. I'm Jim.

B. That's Jim.

C. This is Jim speaking.

D. He is Jim.

Web应用软件的性能测试主要包括 ______。

A．并发测试

B．负载测试和压力测试
C．配置测试和性能调优
D．以上全部