A TCP/IP application receives files from a remote machine. The application reads 32 kilobytes of data at a time to the socket， but has not issued a system call to set the window size. Which of the following procedures should be performed on the personal machine to increase the throughput of the application？（）
- A Increase the size of thewall
- B Increase the size of sb_max
- C Increase the size of tcp_recvspace
- D Increase the size of tcp_sendspace