What does an API gateway primarily do with respect to internal topology?

• A. Exposes all internal service addresses to clients.
• B. Directly stores user data for all services.
• C. Generates client code automatically.
• D. Abstracts the internal topology from clients.

Answer: (D)

The main idea here is that an API gateway sits at the edge as a single entry point and hides the internal layout of services from clients. By presenting a stable external interface, it routes requests to the appropriate microservices behind the scenes, without exposing how those services are arranged, where they live, or how many of them there are. This abstraction lets the internal topology change—services scale up or down, move, or get replaced—without breaking external clients, because the gateway keeps the outside world insulated from those details.

That’s why the best answer is to abstract the internal topology from clients. The gateway also handles cross-cutting concerns like authentication, rate limiting, and load balancing, but its core value here is providing a consistent external view while managing the routing to the real services.

Why the others don’t fit: exposing all internal service addresses would reveal the internal layout and tie clients to it, compromising security and flexibility. storing user data is outside the gateway’s purpose, which is routing and interface management, not data storage. generating client code automatically is a separate capability often handled by API design tooling or SDK generators, not by the gateway itself.