A REST API is being designed to implement a Mule application.
What standard interface definition language can be used to define REST APIs?

Refer to the exhibit.
An organization is designing a Mule application to receive data from one external business partner. The two companies currently have no shared IT infrastructure and do not want to establish one. Instead, all communication should be over the public internet (with no VPN).
What Anypoint Connector can be used in the organization's Mule application to securely receive data from this external business partner?

An ABC Farms project team is planning to build a new API that is required to work with data from different domains across the organization.
The organization has a policy that all project teams should leverage existing investments by reusing existing APIs and related resources and documentation that other project teams have already developed and deployed.
To support reuse, where on Anypoint Platform should the project team go to discover and read existing APIs, discover related resources and documentation, and interact with mocked versions of those APIs?

A new Mule application under development must implement extensive data transformation logic. Some of the data transformation functionality is already available as external transformation services that are mature and widely used across the organization; the rest is highly specific to the new Mule application.
The organization follows a rigorous testing approach, where every service and application must be extensively acceptance tested before it is allowed to go into production.
What is the best way to implement the data transformation logic for this new Mule application while minimizing the overall testing effort?

Refer to the exhibit.

A shopping cart checkout process consists of a web store backend sending a sequence of API invocations to an Experience API, which in turn invokes a Process API. All API invocations are over HTTPS POST. The Java web store backend executes in a Java EE application server, while all API implementations are Mule applications executing in a customer -hosted Mule runtime.
End-to-end correlation of all HTTP requests and responses belonging to each individual checkout Instance is required. This is to be done through a common correlation ID, so that all log entries written by the web store backend, Experience API implementation, and Process API implementation include the same correlation ID for all requests and responses belonging to the same checkout instance.
What is the most efficient way (using the least amount of custom coding or configuration) for the web store backend and the implementations of the Experience API and Process API to participate in end-to-end correlation of the API invocations for each checkout instance?