You are a Microsoft 365 administrator for your company, where all users are assigned Microsoft 365 E3 licenses. The security team requests that a select group of users gain access to Microsoft Defender for Office 365 features to improve email security.
What is the most cost-effective way to fulfill this requirement?
Purchase Microsoft 365 E5 licenses for all users
Purchase Microsoft Defender for Office 365 add-on licenses for the specified users
Upgrade the base licenses of the specified users from Microsoft 365 E3 to Microsoft 365 E5
Enable Microsoft Defender for Office 365 features in the admin center without additional licenses