What is meant by 'clear responsibility' in module design?

• A. A module should perform as many tasks as possible.
• B. Each module or component should have a well-defined purpose and interface, with minimal responsibilities.
• C. Interfaces should be opaque and complex.
• D. Responsibilities should be distributed randomly.

Answer: (B)

Clear responsibility means each module has a well-defined purpose and a clean, minimal interface. It aligns with the idea that a module should do one thing and do it well, exposing only what is necessary to use it. When a module has a focused task, it stays cohesive and is easier to test, maintain, and reuse, because changes in one area are less likely to affect others. A straightforward interface communicates how the module should be used without revealing internal details, which supports encapsulation and information hiding.

This is the best description because it directly captures the idea of having a precise, limited role for each module. The other options clash with this approach: trying to have a module perform many tasks blurs its purpose; interfaces that are opaque and complex make usage and maintenance hard; distributing responsibilities randomly shows no deliberate design.