Which of the following is considered a performance obligation under revenue recognition?

Delivering goods or services as per contract is considered a performance obligation under revenue recognition because it directly correlates with the recognition of revenue in accordance with IFRS 15, "Revenue from Contracts with Customers." A performance obligation refers to a promise in a contract to transfer a distinct good or service to the customer. When a business fulfills this obligation by delivering the agreed-upon goods or services, it can recognize revenue as this is the point at which control of the asset has transferred to the customer.

The other choices do not qualify as performance obligations. Identifying the customer is a preparatory step in the process of contract management but does not involve the transfer of goods or services. Collecting payment is a financial activity that occurs after revenue recognition has taken place; it does not affect the obligation itself. Advertising the performance may help in attracting customers, but it is not related to the contractual obligations between the seller and buyer, and thus does not constitute a performance obligation in the context of revenue recognition.