A team hired for on-site work must perform remotely; some members returned home and request reimbursement for operational expenses. What should the project manager do?

The correct answer is to follow the Perform Integrated Change Control process and submit a change request. This is because significant changes to project scope, budget, or resources, such as unexpected operational expenses due to a shift from on-site to remote work, require formal evaluation and approval to maintain project control and ensure all stakeholders are aware and agree. This process ensures the change is assessed for its impact on the entire project and documented appropriately. Reviewing the budget and allocating funds (without formal change control) or simply updating the project management plan are reactive steps that bypass the necessary approval process for a substantial change. Asking for justification is part of the information gathering but doesn't constitute the formal change control process itself.