Which of the following is a built-in validation type?

The correct answer is about mandatory fields and data type compliance, which are essential components of built-in validation types in OutSystems. This validation ensures that the data entered into an application meets the required criteria before it can be processed.

Mandatory fields check if certain input fields are filled out; if a required field is left empty, it will prompt the user to provide the necessary information. Data type compliance ensures that the data entered matches the expected data types, avoiding issues such as entering text into a numeric field, which can lead to runtime errors or data inconsistency.

These built-in validations are crucial in maintaining data integrity and ensuring that only valid data is processed within the application. By using these types of validations, developers can create a more robust user experience.

Other options such as conditional statements and custom logic verification may involve additional programming or logic that is not inherently built into the validation framework, and load testing validations focus on performance rather than data integrity. Hence, while they are important in different contexts, they do not fall under the category of built-in validation types like mandatory fields and data type compliance do.