The customer requests ongoing support and maintenance after the rollout.

To ensure effective ongoing support and maintenance after the rollout of a Salesforce project, all the elements listed are essential: A. Establishing a support channel is crucial for a responsive troubleshooting and issue-reporting mechanism. B. Regular system updates and patches are necessary to maintain system health and performance, ensuring that bugs are fixed and improvements are implemented regularly. C. Periodic user training sessions help users stay up-to-date with new features and updates, which is essential for maximizing the adoption and utility of the system.

Collectively, these elements create a robust support structure that facilitates continuous improvement and user engagement. Salesforce offers guidance on establishing these elements in their best practices for system maintenance and user training.

More about ongoing support and maintenance best practices can be found here:https://admin.salesforce.com/