Which Salesforce write action is used to create new records in the defined object?

The action used to create new records in a defined object in Salesforce is indeed the "Create" action. This write action specifically targets adding new entries to Salesforce, allowing you to define the necessary fields and data needed for the new record.

When you use the Create action, it generates a brand-new record based on the specified structure of the object, ensuring that all mandatory fields are filled in correctly. This is crucial for maintaining data integrity and adhering to Salesforce's requirements for new record creation.

The other actions, such as Update and Delete, serve different purposes. Update modifies existing records, while Delete removes them entirely. Upsert, on the other hand, combines the functions of both Create and Update, as it can either create new records or update existing ones based on whether a record already exists. However, for the sole purpose of creating new records, the Create action is the appropriate choice.

Thus, the clarity of the Create action as a dedicated function for introducing new records is what makes it the correct answer in this context.