The correct answer is Change the system user default preference "Email format" to HTML and click Apply to enforce it for every user.

Change the system user default preference "Email format" to HTML and click Apply to enforce it for every user updates the global preference in the instance administration and applying the change enforces it for existing accounts. This ensures that notification messages are delivered as HTML with clickable links and inline images for all users without requiring each person to update their own settings.

Create a support ticket with the software vendor and request that they change every user to receive HTML email is incorrect because changing user preferences is an administrative action that you can perform within the application and does not require the vendor to edit every account.

Adjust the outgoing notification templates to always wrap messages in HTML is incorrect because templates control message content but they do not override a user preference that forces plain text rendering. If a user preference is set to plain text they may still receive plain text versions.

Send all users a step by step message explaining how to change their own notification format settings is incorrect because it is inefficient and unnecessary when there is a system default that an administrator can set and apply globally.

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