Final answer:
Billy, the Teams Administrator at Contoso Ltd, should activate the Teams Preview Mode to get early access to unreleased Microsoft Teams features. This allows for testing and preparing for user readiness of new services and capabilities.
Step-by-step explanation:
If Billy is the Teams Administrator at Contoso Ltd and wants to test upcoming Microsoft Teams features to prepare for user readiness, he should C) Activate the Teams Preview Mode.
Teams Preview Mode enables users to access early release features before they are made generally available. This mode is part of the Teams Public Preview program which is ideal for administrators and IT pros who want to test and understand new features to help their organization plan and adopt new services and capabilities. To activate the preview mode, Billy needs to set the Teams update policy to 'Show preview features' for the users who need to test the features. This can be done from the Teams Admin Center under the Teams update policies section.
It's important to note that enabling this option does not automatically enroll the user in any insider or beta program. It specifically activates the in-client option to opt-in to preview mode, which allows the user to get an early look at features in development.