You work as a Systems Administrator for your company. The company has recently purchased a subscription to Microsoft 365. All users in your company have a Microsoft 365 E5 license. You have deployed Microsoft Teams to all users in the company. Several teams and channels have been configured. External contractors can access Microsoft Teams using guest accounts. You need to configure the environment to ensure that no files containing malware can be opened from Microsoft Teams channels by either company users or external contractors. Which of the following should you configure? 

Answer options:

A. Sensitivity labels.
B. Advanced Threat Protection
C. Protected Identity Management
D. Conditional Access policy

B