Explanation:
Before updating and increasing their session timeout setting, the admin should review the following three considerations:

Frustration of users upon timeouts. The admin should consider how users feel when their sessions expire and they have to log in again. Increasing the session timeout setting can reduce user frustration and improve user experience by allowing them to stay logged in longer.

Security risk of unauthorized users for longer timeout settings. The admin should consider how longer timeout settings can increase the security risk of unauthorized users accessing Marketing Cloud. Increasing the session timeout setting can expose user accounts and data to potential threats if users leave their devices unattended or share them with others.

Change impacts all users. The admin should consider how changing the session timeout setting will affect all users within their account or business unit. Increasing the session timeout setting will apply to all users who log in to Marketing Cloud after the change, regardless of their roles or permissions. The other option is incorrect because:

Typical length of time users spend in Marketing Cloud. This is not a consideration for updating and increasing their session timeout setting, as it does not affect the security or user experience of Marketing Cloud. The typical length of time users spend in Marketing Cloud may vary depending on their tasks and needs, but it does not determine how long their sessions should last before expiring.