The question is asking what item types can be retained when implementing Microsoft Teams retention policies in Microsoft 365 E5.

Retention policies in Teams can apply to:

Teams chat messages (1:1 or group chats)

Teams channel messages

Items within those messages, including text, links, and supported embedded objects.

Step 2 – Supported Teams retention items

According to Microsoft documentation:

Retention policies support Teams messages (chats and channel posts) and their associated attachments or in-line content such as:

Embedded images

Code snippets

Tables, links, and reactions

Retention policies do not support certain Teams items, including:

Voicemails

Calls and meetings recordings

Whiteboards

Message reactions (stored separately in Azure services)