单选题：Two spam mail detection systems are tested on a dataset with 100

Two spam mail detection systems are tested on a dataset with 10000 ordinary mails and 2000 spam mails. System A detects 300 ordinary mails and 1600 spam mails, and system B detects 315 ordinary mails and 1800 spam mails. If our primary concern is to keep the important mails safe, which of the following is correct? @[C](3)

A. Precision is our primary concern and system A is better.
B. Recall is our primary concern and system B is better.
C. Precision is our primary concern and system B is better.
D. Recall is our primary concern and system A is better.




A.Precision is our primary concern and system A is better.
B.Recall is our primary concern and system B is better.
C.Precision is our primary concern and system B is better.
D.Recall is our primary concern and system A is better.


答案：C