To examine the Exhibit， press the Exhibit button. While a user is compiling a C program， "vmstat 120 10" is run to determine the cause of a performance problem.  Using the vmstat output as shown in the exhibit， which of the following conclusions is most appropriate to draw about the I/O bottleneck？（）

• A、 The bottleneck is network I/O.
• B、 The bottleneck is local disk I/O.
• C、 The bottleneck is paging space I/O.
• D、 The bottleneck is to a remote filesystem.