Which of the following security policies is BEST to use when trying to mitigate the risks involved with allowing a user to access company email via their cell phone？（）

1. A The cell phone should require a password after a set period of inactivity. 正确答案
2. B The cell phone should only be used for company related emails.
3. C The cell phone data should be encrypted according to NIST standards.
4. D The cell phone should have data connection abilities disabled.