What is a key advantage of the Partner WSDL?

The key advantage of the Partner WSDL lies in its flexibility at runtime. The Partner WSDL is designed to accommodate a dynamic environment where the data structures of incoming requests may change frequently. This means that it is capable of handling various objects and data types without being strictly tied to a predefined set of data structures. Consequently, developers can work with a more versatile service interface, allowing for the incorporation of different Salesforce objects and supporting complex integrations.

This flexibility is particularly beneficial in scenarios where applications need to interact with external systems that may not have a fixed schema or when dealing with a variety of business scenarios that require adaptability. The dynamic nature of the Partner WSDL ensures that as new objects and fields are added to Salesforce, they can be easily integrated without the need to modify the WSDL extensively.

In contrast, other options are less advantageous for integration purposes. Limited flexibility at design-time suggests restrictions that are counterproductive for evolving integration needs, while using specific classes only can hinder integration with a broader range of Salesforce objects. Saying that it is only suitable for static data would imply limitations that do not align with the dynamic nature of many modern integration use cases.