单选题：Given a set of 20000 emails in the mailbox, our task is to retri

Given a set of 20000 emails in the mailbox, our task is to retrieve the spam emails from this set. The statistic data for a spam filter's performance are shown in the following table. The precision of this filter is: ___.


| Category | Actual True Spam | Actual False Spam |
| -------- | :--------: | :--------: |
| Retrieved True Spam | 3000 | 6000 |
| Retrieved False Spam | 5000 | 6000 |









A.50%


B.33.3%


C.37.5%


D.45.5%




答案：B