A worker processes messages from a Service Bus queue (QueueA). For each message, it must send a notification to a topic (TopicB) and a command to another queue (QueueC), then complete the original message. All three operations must succeed or fail together. What should you do?

The correct options address the requirement for atomicity across multiple Service Bus operations. Performing the receive-complete on QueueA and the sends to TopicB and QueueC inside a Service Bus transaction (TransactionScope or ServiceBusTransaction) using the same ServiceBusClient connection ensures that all these operations are treated as a single atomic unit. If any operation within the transaction fails, all operations are rolled back, guaranteeing an "all or nothing" outcome. This is a core feature of Service Bus transactions. Ensuring QueueA, TopicB, and QueueC are in the same Service Bus namespace is a prerequisite for Service Bus transactions to function. Transactions in Azure Service Bus are scoped to a single namespace. Using separate ServiceBusClient instances would prevent transactional behavior, as each instance would operate independently. Enabling duplicate detection on entities does not guarantee atomicity across multiple distinct operations; it only prevents processing the same message twice. Azure Functions with multiple output bindings do not inherently guarantee atomic commits across different Service Bus entities in the way a Service Bus transaction does; the function runtime ensures the function execution, but not the transactional integrity of external services.