A NewsletterSubscription custom object exists that has a key attribute named email of type String...

The call syntax shown is valid:CustomObjectMgr.createCustomObject(type, keyValue)accepts the object type followed by the unique key value. The issue is persistence. A custom object is a persistent business object, so creation or modification must occur within a B2C Commerce database transaction.

Salesforce ' sTransactiondocumentation states thatbefore a persistent business object can be created, changed, or deleted, a transaction must be started. Changes become durable only after that transaction is successfully committed. The usual SFRA implementation pattern isTransaction.wrap(function () { ... });, although explicitbegin()andcommit()operations are also supported.

Atry/catchblock provides exception handling but does not establish transactional persistence, so option B does not solve the fundamental issue. Option C is incorrect because the API does not accept a third argument representing the key attribute name. The object ' s metadata already establishes which attribute is its key.

Transactions should cover only the minimum necessary mutation logic to reduce locking and maintain efficient storefront processing.

Study Guide reference:Application Development — persistent objects,CustomObjectMgr,dw.system.Transaction, transaction boundaries, and custom-object persistence.

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